Scott A. Crooker

Technical Staff Member
National High Magnetic Field Laboratory
Ph.D., Physics, University of California, Santa Barbara, 1997
B.A., Physics, Cornell University, 1992

Address:
National High Magnetic Field Laboratory
Los Alamos National Laboratory
Mail Stop E536
Los Alamos, New Mexico 87545 USA

Phone: (505) 665-7595
Lab: (505) 667-4323
Fax: (505) 665-4311
e-mail: crooker _at_ lanl.gov

Here's a link to my 'official' NHMFL page

Current Research Projects

Spin/valley dynamics of electrons, holes, and excitons in monolayer semiconductors. Using ultrafast time-resolved Kerr rotation and also "valley noise spectroscopy", we probe the coupled spin and valley dynamics of resident electrons and holes that are doped into monolayer semiconductors such as MoS₂, WSe₂, MoSe₂, and WS₂. We've recently observed a long spin lifetime for resident electrons (order 100ns), and a very long spin/valley lifetime for resident holes (order 2 microseconds), confirming longstanding predictions of strong spin-valley locking in the valence band of these monolayer transition-metal dichalcogenide semiconductors [ Phys. Rev. Materials 5, 044001 (2021) , Sci. Adv. 5, eaau4889 (2019) , PRL 119, 137401 (2017) , Nano Letters 15, 8250 (2015) , Nature Physics 11, 830 (2015) ]. In collaboration with the groups of Xiaodong Xu (University of Washington), with Xavier Marie, Bernhard Urbaszek, and Cedric Robert (INSA-Toulouse), and with Jun Lou (Rice University).

Polarized optical spectroscopy of monolayer semiconductors in (very) high magnetic fields. Using a sample-on-fiber approach, we perform polarization-resolved magneto-reflection and magneto-absorption spectroscopy -- in pulsed magnetic fields up to (and exceeding) 65T -- of monolayer semiconductors such as MoS₂, WSe₂, MoSe₂, and WS₂. In addition to clear valley Zeeman effects, these high-field studies also reveal the small diamagnetic shifts of the excitons and their excited Rydberg states, from which we can infer the exciton mass, binding energy, and size, as well as important dielectric screening lengths [ Nat. Comm. 10, 4172 (2019), PRL 120, 057405 (2018) , Nature Comm 7, 10643 (2016) ]. We have also used this method to measure the (significant and unavoidable) influence of dielectric screening on a 2D semiconductor when it is stacked in a van der Waals heterostructure [ Nano Letters 16, 7054 (2016) ]. In collaboration with Berry Jonker and Kathy McCreary (Naval Research Lab), and with Nathan Wilson and Xiaodong Xu (University of Washington), and with Xavier Marie, Bernhard Urbaszek, and Cedric Robert (INSA-Toulouse).

Many-body correlations in charge-tunable monolayer semiconductors. Recent studies of electrostatically-gated single WSe₂ monolayers, at low temparatures and in high magnetic fields, have revealed strong experimental evidence for spontaneous valley polarization of holes (in p-type WSe₂) [ PRL 125, 147602 (2020) ], and for many-body exciton states (6-particle 'hexcitons' and 8-particle 'oxcitons') in electron-doped WSe₂ monolayers [ Nano Letters 22, 426 (2022) ].

Magnetic monopole noise in artificial spin ices (ASIs). Using optical methods to detect spontaneous magnetization fluctuations, we explore the magnetic-field-dependent phase diagram of various ASI lattices. In the archetypal square ASI lattice, we reveal plasma-like regimes where emergent monopole-like magnetic excitations proliferate and diffuse throughout the lattice, in thermal equilibrium. The frequency spectrum of this monopole noise through the monopole regime is measured. [ Physical Review X 11, 011402 (2021) , Physical Review B 105, 094406 (2022) ]

Spin & magnetization noise spectroscopy in semiconductors and ferromagnetic metals. Using methods for ultrasensitive magneto-optical Faraday and/or Kerr rotation, we passively "listen" to the intrinsic, stochastic magnetization fluctuations that exist in an equilibrium spins system (in our case, electrons and holes trapped in InGaAs self-assembled quantum dots, and also in bulk n-type GaAs). In accord with the fluctuation-dissipation theorem, we study how these fluctuations alone can be used to perform detailed magnetic resonance of the system under study, without ever perturbing the system away from thermal equilibrium [e.g., Nature Communications 5, 4949 (2014) , Phys. Rev. Lett (2012), Phys. Rev. Lett (2010), Phys. Rev. B (2009) & Nature (2004); Phys. Rev. A (2006) & Phys. Rev. A (2006)]. A number of interesting studies can also be performed in atomic alkali vapors. [ Physical Review Letters 113, 156601 (2014) , arXiv:1408.5399 ] (in collaboration with theoreticians Darryl Smith and Nikolai Sinitsyn at Los Alamos, and the group of Profs. Manfred Bayer and Dmitri Yakovlev at TU-Dortmund). Most recently we have measured magnetization noise in ultrathin Pt/Co/Pt ferromagnetic films, and observed how the frequency spectrum of magnetization fluctuations evolves as the sample is tuned through a spin-reorientation transition [ Physical Review X 8, 031378 (2018) ]. Also, more recently we adapted these methods to measure the intrinsic 'valley noise' of carriers in a monolayer semiconductor [ Science Advances 5, eaau4899 (2019)].

Time-domain terahertz spectroscopy in pulsed magnetic fields. We developed a table-top 31 T pulsed magnet with free-space optical access, for time-domain THz spectroscopy of correlated electron systems in high magnetic fields. Recently we used this system to perform cyclotron resonance of holes in the cuprate superconductor LSCO [ Physical Review B 103, 134515 (2021) , Physical Review B 106, 195110 (2022) ]. These measurements allow determination of high-frequency complex conductivities in the range 100-1500 GHz. In collaboration with group of Prof. Peter Armitage.

Spin-polarized excitons in colloidal semiconductor nanocrystal quantum dots and magnetically-doped nanocrystals are investigated with static- and time-resolved optical spectroscopy in high magnetic fields and low temperatures [e.g., ACS Nano (2021) , Nat. Nano. (2016), Nat. Nano. (2012), Phys. Rev. Lett. (2011), Nat. Mat. (2009), Htoon et al Phys Rev. Lett. (2009) & PRB (2008); Furis et al J. Phys. Chem. B (2005)]. In other studies, we resonantly photoinject spin-up or spin-down excitons into CdSe nanocrystals at high magnetic fields, and detect the near-resonant polarized emission from nearby exciton spin levels, with an aim of revealing the "fine structure" within the exciton states in nanocrystals [Furis et al Phys. Rev. B Rapid Comm (2006)]. Polarization-resolved, low-temperature, high-B, single-nanocrystal PL microscopy studies are also currently underway [e.g., Htoon et al, PRB (2007)] (in collaboration with the group of Dr. Victor Klimov at Los Alamos).

2-D imaging of optically- and electrically-injected spin currents in semiconductors for "spintronic" applications. Using techniques for scanning magneto-optical Kerr-rotation microscopy, we spatially image the injection, lateral transport, and manipulation of spin-polarized electrons in GaAs. The drift, diffusion, and precession of optically-injected spins are imaged in the presence of applied electric, magnetic, and strain fields, applied individually or in combination [Crooker et al, PRL (2005); Hruska et al, PRB (2006); Furis et al, New J. Physics (2007)]. Similar techniques are used to image and investigate electrically-injected spin currents in hybrid Fe/GaAs ferromagnet-semiconductor spin transport devices. Measurements reveal efficient electrical spin injection, spin transport and manipulation, spin accumulation, and electrical spin detection in single devices [Crooker et al PRB Rapid Comm (2009); Science (2005); X. Lou et al PRL (2006); X. Lou et al Nature Physics (2007)] (in collaboration with Prof. Paul Crowell at U. Minnesota and Prof. Chris Palmstrom at UCSB).

Experimental Techniques & Capabilities

Low-temperature, scanning magneto-optical Kerr-rotation spectroscopy (for spin & magnetization imaging in semiconductors and ferromagnets).
Magneto-optical spin noise spectroscopy (for measuring intrinsic, fundamental spin fluctuations in semiconductor, metal, & atomic systems).
Ultrafast, coherent time-domain terahertz spectroscopy in high B fields to 18 T (for complex conductivity measurements from 100-1500 GHz in high B fields).
Resonant, spin-polarized PL excitation spectroscopy in high fields to 33 Tesla (for spin-selective PLE and fluorescence-line-narrowing studies in high B).
High-speed "linear" optical spectroscopy in pulsed magnetic fields to 90 Tesla (PL, absorption, reflectivity studies in the 10-1000 ms duration pulsed magnets).
Time-correlated single-photon counting in dc & pulsed magnetic fields (for time-resolved PL in high B; ~35ps resolution).
Low-temperature, polarization-resolved confocal microscopy (for polarized magneto-PL of single colloidal CdSe nanocrystal quantum dots).

Group Members

some photos...

Alumni: Junho Choi (now at KRISS, Korea), Jing Li (now professor at U. Wuhan), Mateusz Goryca (now professor at U. Warsaw), Kirk Post (now surfing in San Diego, but doing good science too at ASML), Andreas Stier (now at TU-Munich), Andrew Balk, Prasenjit Dey (now at Intel), Luyi Yang (now professor at Tsinghua U.), Bill Rice (now at Draper Labs), Yan Li (now Professor at U. Utah), Lili Cheng, Xuan Gao (now Professor at Case-Western University), Madalina Furis (now Professor at University of Oklahoma), Todd Barrick (now Staff Scientist, Sandia National Laboratory), Quinn McCulloch (LANL), Jin-Young Sohn (Korea), Nicolas Negre (France).

Journal Publications

Submitted/in press

Proximity-enhanced valley Zeeman splitting at the WS₂/graphene interface
Paulo E. Faria Junior, Thomas Naimer, Kathleen M. McCreary, Berend T. Jonker, Jonathan J. Finley, Scott A. Crooker, Jaroslav Fabian, Andreas V. Stier
arXiv:2301.122234
Weak dispersion of exciton Lande factor with band gap energy in lead halide perovskites: Approximate compensation of the electron and hole dependences
N. E. Kopteva, D. R. Yakovlev, E. Kirstein, E. A. Zhukov, D. Kudlacik, I. V. Kalitukha, V. F. Sapega, D. N. Dirin, M. V. Kovalenko, A. Baumann, J. Hocker, V. Dyakonov, S. A. Crooker, M. Bayer
arXiv:2301.12775
Proximity Induced Chiral Quantum Light Generation in Strain-Engineered WSe₂/NiPS₃ Heterostructures
X. Li, A. C Jones, J. Choi, H. Zhao, V. Chandrasekaran, M. T. Pettes, A. Piryatinski, N. Sinitsyn, S. A Crooker, H. Htoon
arXiv:2203.00797

Published

Asymmetric magnetic proximity interactions in MoSe₂/CrBr₃ van der Waals heterostructures
Junho Choi, Christopher Lane, Jian-Xin Zhu, Scott A. Crooker
Nature Materials 22, 305 (2023)

Six-Body and Eight-Body Exciton States in Monolayer WSe₂
D. Van Tuan, S.F. Shi, X. Xu, S.A. Crooker, H. Dery
Physical Review Letters 129, 076801 (2022)

Optical detection of long electron spin transport lengths in a monolayer semiconductor
L. Ren, L. Lombez, C. Robert, D. Beret, D. Lagarde, B. Urbaszek, P. Renucci, T. Taniguchi, K. Watanabe, S. A. Crooker, X. Marie
Physical Review Letters 129, 027402 (2022)

Many-Body Exciton and Intervalley Correlations in Heavily Electron-Doped WSe₂ Monolayers
Jing Li, Mateusz Goryca, Junho Choi, Xiaodong Xu, Scott A Crooker
Nano Letters 22, 426 (2022)

Evolution of the cyclotron mass with doping in La_2-xSr_xCuO₄
A. Legros, K. W. Post, P. Chauhan, D. G. Rickel, Xi He, X. Xu, X. Shi, I. Bozovic, S. A. Crooker, and N. P. Armitage
Physical Review B 106, 195110 (2022)

Magnetic field dependent thermodynamic properties of square and quadrupolar artificial spin ice
M. Goryca, X. Zhang, J. Li, A. L. Balk, J. D. Watts, C. Leighton, C. Nisoli, P. Schiffer, S. A. Crooker
Physical Review B 105, 094406 (2022)

Nonreciprocal directional dichroism at telecom wavelengths
K. Park, M. O. Yokosuk, M. Goryca, J. J. Yang, S. A. Crooker, S.-W. Cheong, K. Haule, D. Vanderbilt, H.-S. Kim, J. L. Musfeldt
npj Quantum Materials 7, 38 (2022)

Dative Epitaxy of Commensurate Monocrystalline Covalent van der Waals Moire Supercrystal
M. Bian, L. Zhu, X. Wang, J. Choi, R. V. Chopdekar, S. Wei, L. Wu, C. Huai, A. Marga, Q. Yang, Y. C. Li, F.Yao, T. Yu, S. A. Crooker, X. M. Cheng, R. F. Sabirianov, S. Zhang, J. Lin, Y. Hou, H. Zeng
Advanced Materials 2022, 2200117 (2022)

Field-Induced Magnetic Monopole Plasma in Artificial Spin Ice
M. Goryca, X. Zhang, J. Li, A. L. Balk, J. D. Watts, C. Leighton, C. Nisoli, P. Schiffer, S. A. Crooker
Physical Review X 11, 011402 (2021)

Valley relaxation of resident electrons and holes in a monolayer semiconductor: Dependence on carrier density and the role of substrate-induced disorder
Jing Li, M. Goryca, K. Yumigeta, H. Li, S. Tongay, S. A. Crooker
Physical Review Materials 5, 044001 (2021)

Observation of cyclotron resonance and measurement of the hole mass in optimally-doped La_2-xSr_xCuO₄
K.W. Post, A. Legros, D. G. Rickel, J. Singleton, R. D. McDonald, Xi He, I. Bozovic, X. Xu, X. Shi, N. P. Armitage, S. A. Crooker
Physical Review B 103, 134515 (2021)

Enhanced Emission from Bright Excitons in Asymmetrically Strained Colloidal CdSe/CdZnSe Quantum Dots
I. Fedin, M. Goryca, D. Liu, S. Tretiak, V. I. Klimov, S. A. Crooker
ACS Nano 15, 14444 (2021)

Covalent 2D Cr₂Te₃ ferromagnet
M. Bian, A. Kamenskii, M. Han, W. Li, S. Wei, X. Tian, D. B. Eason, F. Sun, K. He, H. Hui, F. Yao, R. Sabirianov, J. P. Bird, C. Yang, J. Miao, J. Lin, S. A. Crooker, Y. Hou, H. Zeng
Materials Research Letters 9, 205 (2021)

Optical and Magneto-Optical Properties of Donor-Bound Excitons in Vacancy-Engineered Colloidal Nanocrystals
F. Carulli, V. Pinchetti, M. L. Zaffalon, A. Camellini, S. Rotta Loria, F. Moro, M. Fanciulli, M. Zavelani-Rossi, F. Meinardi, S. A. Crooker, S. Brovelli
Nano Letters 21, 6211 (2021)

Intrinsic and Extrinsic Exciton Recombination Pathways in AgInS_2 Colloidal Nanocrystals
M. L. Zaffalon, V. Pinchetti, A. Camellini, S. Vikulov, C. Capitani, B. Bai, M. Xu, F. Meinardi, J. Zhang, L. Manna, M. Zavelani-Rossi, S. A. Crooker, S. Brovelli
Energy Material Advances 2021, 1959321 (2021)

Spontaneous Valley Polarization of Interacting Carriers in a Monolayer Semiconductor
J. Li, M. Goryca, N. P. Wilson, A. V. Stier, X. Xu, and S. A. Crooker
Physical Review Letters 125, 147602 (2020)

GaN/AlGaN 2DEGs in the quantum regime: Magneto-transport and photoluminescence to 60 tesla
S. A. Crooker, M. Lee, R. D. McDonald, J. L. Doorn, I. Zimmermann, Y. Lai, L. E. Winter, Y. Ren, Y. J. Cho, B. J. Ramshaw, H. G. Xing, D. Jena
Applied Physics Letters 117, 262105 (2020)

Exploiting Functional Impurities for Fast and Efficient Incorporation of Manganese into Quantum Dots
H. Jin, M. Goryca, M. Janicke, S. A. Crooker, V. I. Klimov
JACS 142, 18160 (2020)

Negatively Charged Excitons in CdSe Nanoplatelets
E. V. Shornikova, D. R. Yakovlev, L. Biadala, S. A. Crooker, V. V. Belykh, M. V. Kochiev, A. Kuntzmann, M. Nasilowski, B. Dubertret, and M. Bayer
Nano Letters 20, 1370 (2020)

Nonreciprocal directional dichroism of a chiral magnet in the visible range
M. Yokosuk, H. Kim, K. Hughey, J. Kim, AV Stier, KR O'Neal, JJ Yang, SA Crooker, K. Haule, SW Cheong, D. Vanderbilt, and JL Musfeldt
npj Quantum Materials 5, 20 (2020)

Spectroscopic and Magneto-Optical Signatures of Cu¹⁺ and Cu²⁺ Defects in Copper Indium Sulfide Quantum Dots
A. Fuhr, HJ Yun, SA Crooker, and VI Klimov
ACS Nano 14, 2212 (2020)

Revealing exciton masses and dielectric properties of monolayer semiconductors with high magnetic fields
M. Goryca, J. Li, A. V. Stier, T. Taniguchi, K. Watanabe, E. Courtade, S. Shree, C. Robert, B. Urbaszek, X. Marie, and S. A. Crooker
Nature Communications 10, 4172 (2019)

Detection of thermodynamic valley noise in monolayer semiconductors: access to intrinsic relaxation times
M. Goryca, N. P. Wilson, P. Dey, X. Xu, S. A. Crooker
Science Advances 5, eaau4899 (2019)

Room-temperature magnetic order in air-stable ultra-thin iron oxide
J. Yuan, A. Balk, H. Guo, S. Patel, X. Zhao, Q. Fang, D. Natelson, S. A. Crooker, J. Lou
Nano Letters 19, 3777 (2019)

Dual-Emitting Dot-in-Bulk CdSe/CdS Nanocrystals with Highly Emissive Core- and Shell-Based Trions Sharing the Same Resident Electron
V. Pinchetti, EV Shornikova, G. Qiang, WK Bae, . Meinardi, SA Crooker, DR YAkovlev, M. Bayer, VI Klimov, S. Brovelli
Nano Letters 19, 8846 (2019)

Comparing the anomalous Hall effect and the magneto-optical Kerr effect through antiferromagnetic phase transitions in Mn₃Sn
A. L. Balk, N. H. Sung, S. M. Thomas, P. F. S. Rosa, R. D. McDonald, J. D. Thompson, E. D. Bauer, F. Ronning, S. A. Crooker
Applied Physics Letters 114, 032401 (2019)

Quantized Electronic Doping towards Atomically Controlled "Charge-Engineered" Semiconductor Nanocrystals
C. Capitani, V. Pinchetti, G. Gariano, B. Santiago-Gonzalez, C. Santambrogio, M. Campione, M. Prato, R. Brescia, A. Camellini, F. Bellato, F. Carulli, A. Anand, M. Zavelani-Rossi, F. Meinardi, S. A. Crooker, S. Brovelli
Nano Letters 19, 1307 (2019)

Evidence for the Band-Edge Exciton of CuInS₂ Nanocrystals Enables Record Efficient Large-Area Luminescent Solar Concentrators
A. Anand, ML Zaffalon, G. Gariano, A. Camellini, M. Gandini, R. Brescia, C. Capitani, F. Bruni, V. Pinchetti, M. Zavelani-Rossi, F. Meinardi, S. A. Crooker, S. Brovelli
Advanced Functional Materials 30, 1906629 (2019)

Determination of the In-Plane Exciton Radius in 2D CdSe Nanoplatelets via Magneto-optical Spectroscopy
A. Brumberg, S. M. Harvey,J. P. Philbin, B. T. Diroll, B. Lee, S. A. Crooker, M. R. Wasielewski, E. Rabani, R. D. Schaller
ACS Nano 13, 8589 (2019)

Broadband spectroscopy of thermodynamic magnetization fluctuations through a ferromagnetic spin-reorientation transition
A. Balk, F. Li, I. Gilbert, J. Unguris, N. A. Sinitsyn, S. A. Crooker
Physical Review X 8, 031378 (2018)

Magnetooptics of Exciton Rydberg States in a Monolayer Semiconductor
A. V. Stier, N. P. Wilson, K. A. Velizhanin, J. Kono, X. Xu, S. A. Crooker
Physical Review Letters 120, 057405 (2018)

Excitonic pathway to photoinduced magnetism in colloidal nanocrystals with nonmagnetic dopants
V. Pinchetti, Q. Di, M. Lorenzon, A. Camellini, M. Fasoli, M. Zavelani-Rossi, F. Meinardi, J. Zhang, S. A. Crooker, S. Brovelli
Nature Nanotechnology 13, 145 (2018)

Flexible magnetic composites for light-controlled actuation and interfaces
M. Li, Y. Wang, A. Chen, A. Naidu, B. S. Napier, W. Li, C. L. Rodriguez, S. A. Crooker, F. G. Omenetto
Proceedings of the National Academy of Sciences 115, 8119 (2018)

High magnetic fields for fundamental physics
R. Battesti, J. Beard, S. Boser, N. Bruyant, D. Budker, S. A. Crooker, E. Daw et al.
Physics Reports 765-766, 1-39 (2018)

Origin of deep localization in GaAs_1-xBi_x and its consequences for alloy properties
K. Alberi, B. Fluegel, D. A. Beaton, M. Steger, S. A. Crooker, A. Mascarenhas
Physical Review Materials 2, 114603 (2018)

Gate controlled spin-valley locking of resident carriers in WSe₂ monolayers
P. Dey, Luyi Yang, C. Robert, G. Wang, B. Urbaszek, X. Marie, S. A. Crooker
Physical Review Letters 119,137401 (2017)

Superradiant coupling effects in transition-metal dichalcogenides
C. E. Stevens, T. Stroucken, AV Stier, J. Paul, H. Zhang, P. Dey, SA Crooker, SW Koch, & D. Karaiskaj
Optica 5, 749 (2018)

Scaling law for excitons in 2D perovskite quantum wells
J.-C. Blancon, A. V. Stier, H. Tsai, W. Nie, C. C. Stoumpos, B. Traore, L. Pedesseau, M. Kepenekian, S. Tretiak, S. A. Crooker, M. G. Kanatzidis, C. Katan, J. J. Crochet, J. Even, A. D. Mohite
Nature Communications 9, 2254 (2018)

Direct Measurements of Magnetic Polarons in CdMnSe Nanocrystals from Resonant Photoluminescence
W.D. Rice, W. Liu, V. Pinchetti, D. R. Yakovlev, V. I. Klimov, S. A. Crooker
Nano Letters 17, 3068 (2017)

Localization behavior at bound complex states in GaAs_1-xBi_x
K. Alberi, T.M. Christian, B. Fluegel, S. A. Crooker, D. A. Beaton, A. Mascarenhas
Physical Review Materials 1, 024605 (2017)

Fiber Bragg Grating Dilatometry in Extreme Magnetic Field and Cryogenic Conditions
M. Jaime, C.C. Moya, F. Wieckert, V. Zapf, F.F. Balakirev, M. Wartenbe, P.F.S. Rosa, J.B. Betts, G. Rodriguez, S. A. Crooker, R. Daou
Sensors 17, 2572 (2017)

Probing the influence of dielectric environment on excitons in monolayer WSe₂: Insight from high magnetic fields
Andreas V. Stier, Nathan P. Wilson, Genevieve Clark, Xiaodong Xu, Scott A. Crooker
Nano Letters 16, 7054 (2016)

Magnetoreflection spectroscopy of monolayer transition-metal dichalcogenide semiconductors in pulsed magnetic fields
Andreas V. Stier, Kathleen M. McCreary, Berend T. Jonker, Junichiro Kono, Scott A. Crooker
J. Vac. Sci. Tech. B 34, 04J102 (2016)

Exciton diamagnetic shifts and valley Zeeman effects in monolayer WS₂ and MoS₂ to 65 Tesla
Andreas V. Stier, Kathleen M. McCreary, Berend T. Jonker, Junichiro Kono, Scott A. Crooker
Nature Communications 7:10643 (2016)

Revealing giant internal magnetic fields due to spin fluctuations in magnetically-doped nanocrystals
W.D. Rice, W. Liu, T.A. Baker, N. Sinitsyn, V. I. Klimov, S. A. Crooker
Nature Nanotechnology, 11, 137 (2016)

Higher-order spin-noise spectroscopy of atomic spins in fluctuating external fields
F. X. Li, S. A. Crooker, N. A. Sinitsyn
Physical Review A 93, 033814 (2016)

Magnetic field stabilized electron-hole liquid in indirect bandgap AlGaAs
Kirstin Alberi, Brian Fluegel, Scott A. Crooker, Angelo Mascarenhas
Physical Review B 93, 075310 (2016)

Spin coherence and dephasing of localized electrons in monolayer MoS₂
Luyi Yang, Weibing Chen, Kathleen M. McCreary, Berend T. Jonker, Jun Lou, Scott A. Crooker
Nano Letters 15, 8250 (2015)

Long-lived nanosecond spin relaxation and spin coherence of electrons in monolayer MoS₂ and WS₂
Luyi Yang, Nikolai A. Sinitsyn, Weibing Chen, Jiangtan Yuan, Jing Zhang, Jun Lou, Scott A. Crooker
Nature Physics 11, 830 (2015)

Cross-correlation spin noise spectroscopy of heterogeneous interacting spin systems
Dibyendu Roy, Luyi Yang, Scott A. Crooker, Nikolai A. Sinitsyn
Scientific Reports 5, 9573 (2015)

Temperature and magnetic-field dependence of radiative decay in colloidal germanium quantum dots
I. Robel, A. Shabaev, D. C. Lee, R. D. Schaller, J. M. Pietryga, S. A. Crooker, A.L. Efros, V. I. Klimov
Nano Letters 15, 2685 (2015)

Spin noise spectroscopy beyond thermal equilibrium and linear response
P. Glasenapp, Luyi Yang, D. Roy, D. G. Rickel, A. Greilich, M. Bayer, N. A. Sinitsyn, S. A. Crooker
Physical Review Letters 113, 156601 (2014)

Two-color spin noise spectroscopy: Using spin fluctuation correlations to reveal homogeneous linewidths within quantum dot ensembles
Luyi Yang, P. Glasenapp, A. Greilich, D. Reuter, A. D. Wieck, D. R. Yakovlev, M. Bayer, S.A. Crooker
Nature Communications 5, 4949 (2014)

Magnetic field-induced direct-indirect crossover in Al_xGa_1-xAs
K. Alberi, A. V. Mialitsin, B. Fluegel, S. A. Crooker, J. L. Reno, A. Mascarenhas
Applied Physics Express 7, 111201 (2014)

Magneto-optical properties of CuInS₂ nanocrystals
William D. Rice, H. McDaniel, V. I. Klimov, S. A. Crooker
Journal Of Physical Chemistry Letters 5, 4105 (2014)

Magnetoelectroluminescence of organic heterostructures: Analytical theory and spectrally resolved measurements
Feilong Liu, Megan R. Kelley, Scott A. Crooker, Wanyi Nie, Aditya D. Mohite, P. Paul Ruden, Darryl L. Smith
Physical Review B 90, 235314 (2014)

Spectrally resolved hyperfine interactions between polaron and nuclear spins in organic light emitting diodes: magneto-electroluminescence studies
S. A. Crooker, F. Liu, M. R. Kelley, N. J. D. Martinez, W. Nie, A. Mohite, I. H. Nayyar, S. Tretiak, D. L. Smith, P. P. Ruden
Applied Physics Letters 105, 153304 (2014)

Persistent optically induced magnetization in oxygen-deficient strontium titanate
W. D. Rice, P. Ambwani, M. Bombeck, J. D. Thompson, G. Haugstad, C. Leighton, S. A. Crooker
Nature Materials 13, 481 (2014)

Revealing optically induced magnetization in SrTiO₃ using optically-coupled SQUID magnetometry and magnetic circular dichroism
W. D. Rice, P. Ambwani, J. D. Thompson, C. Leighton, S. A. Crooker
Journal of Vacuum Science and Technology B 32, 04E102 (2014) (PCSI-41 conference proceeding)

Optical spectroscopy of spin noise
V. S. Zapasskii, A. Greilich, S. A. Crooker, Yan Li, G. G. Kozlov, D. R. Yakovlev, D. Reuter, A. D. Wieck, M. Bayer
Physical Review Letters 110, 176601 (2013)

Magnetic-field-induced delocalized to localized transformation in GaAs:N
K. Alberi, S. A. Crooker, B. Fluegel, D. A. Beaton, A. J. Ptak, A. Mascarenhas
Physical Review Letters 110, 156405 (2013)

Electrical spin injection and detection in silicon nanowires through oxide tunnel barriers
S. X. Zhang, S. A. Dayeh, Y. Li, S. A. Crooker, D. L. Smith, S. T. Picraux
Nano Letters 13, 430 (2013)

Long-lived photo-induced magnetization in copper-doped ZnSe/CdSe core/shell nanocrystals
A. Pandey, S. Brovelli, R. Viswanatha, L. Li, J. Pietryga, V. I. Klimov, S. A. Crooker
Nature Nanotechnology 7, 792 (2012)

Role of nuclear quadrupole coupling on decoherence and relaxation of central spins in quantum dots
N. A. Sinitsyn, Yan Li, S. A. Crooker, A. Saxena, D. L. Smith
Physical Review Letters 109, 166605 (2012)

Intrinsic spin fluctuations reveal the dynamical response function of holes coupled to nuclear spin baths in (In,Ga)As quantum dots
Yan Li, N. Sinitsyn, D. L. Smith, D. Reuter, A. D. Wieck, D. R. Yakovlev, M. Bayer, S. A. Crooker
Physical Review Letters 108, 186603 (2012)

Magnetostriction and magnetic texture to 100.75 Tesla in frustrated SrCu₂(BO₃)₂
M. Jaime, R. Daou, S. A. Crooker, F. Weickert, A. Uchida, A. Feiguin, C. D. Batista, H. A. Dabkowska, B. D. Gaulin
Proceedings of the National Academy of Sciences 109, 12404 (2012)

A cascade of magnetic field induced spin transitions in LaCoO₃
M. M. Altarawneh, G.-W. Chern, N. Harrison, C. D. Batista, A. Uchida, M. Jaime, D. G. Rickel, S. A. Crooker, C. H. Mielke, J. B. Betts, J. F. Mitchell, M. J. R. Hoch
Physical Review Letters 109, 037201 (2012)

Circular polarization dependent cyclotron resonance in large-area graphene in ultrahigh magnetic fields
L. G. Booshehri, C. H. Mielke, D. G. Rickel, S. A. Crooker, Q. Zhang, L. Ren, E. H. Haroz, A. Rustagi, C. J. Stanton, Z. Jin, Z. Sun, Z. Yan, J. M. Tour, J. Kono
Physical Review B 85, 205407 (2012)

Substrate-controlled ferromagnetism in iron phthalocyanine films due to one-dimensional iron chains
T. Greidig, C. N. Colesniuc, S. A. Crooker, I. K. Schuller
Physical Review B 86, 014409 (2012)

Evolution of superclusters and delocalized states in GaAs_1-xN_x
B. Fluegel, K. Alberi, D. A. Beaton, S. A. Crooker, A. J. Ptak, A. Mascarenhas
Physical Review B 86, 205203 (2012)

[Book Chapter] Spin transport and imaging in III-V ferromagnet-semiconductor heterostructures
P. A. Crowell and S. A. Crooker
In "Spin Transport and Magnetism in Electronic Systems", Eds. I. Zutic and E. Tsymbal (Taylor and Francis, 2011)

Copper-doped inverted core/shell nanocrystals with "permanent" optically active holes
Ranjani Viswanatha, Sergio Brovelli, Anshu Pandey, Scott A. Crooker, and Victor I. Klimov
Nano Letters 11, 4753 (2011)

Spin-polarized Mn²⁺ emission from Mn-doped colloidal nanocrystals (selected for Editor's Suggestion)
R. Viswanatha, J. M. Pietryga, V. I. Klimov, S. A. Crooker
Physical Review Letters 107, 067402 (2011),

Fluorescent single-walled carbon nanotube aerogels in surfactant-free environments
J. G. Duque, C. E. Hamilton, G. Gupta, S. A. Crooker, J. J. Crochet, A. Mohite, H. Htoon, K. A. D. Obrey, A. M. Dattelbaum, S. K. Doorn
ACS Nano 5, 6686 (2011)

Nano-engineered electron-hole exchange interaction controls exciton dynamics in core-shell semiconductor nanocrystals
S. Brovelli, R. D. Schaller, S. A. Crooker, F. Garcia-Santamaria, Y. Chen, R. Viswanatha, J. A. Hollingsworth, H. Htoon, V. I. Klimov
Nature Communications 2, 280 (2011)

[Book Chapter] Coherent spin dynamics of carriers and magnetic ions in diluted magnetic semiconductors
S. A. Crooker
in "Introduction to Diluted Magnetic Semiconductors", Eds. J. Kossut and J. Gaj (Springer-Verlag, 2010)

Breakdown of Volume Scaling in Auger Recombination in CdSe/CdS Heteronanocrystals: The Role of the Core-Shell Interface
F. Garcia-Santamaria, S. Brovelli, R. Viswanatha, J. A. Hollingsworth, H. Htoon, S.A. Crooker, and V. I. Klimov
Nano Letters 11, 687 (2011)

Circularly-polarized photoluminescence from platinum porphyrins in organic hosts: Magnetic field and temperature dependence
C. V. Diaconu, E. R. Batista, R. L. Martin, D. L. Smith, B. K. Crone, and S. A. Crooker
Journal of Applied Physics 109, 073513 (2011).

Spin noise of electrons and holes in self-assembled (In,Ga)As quantum dots
S. A. Crooker, J. Brandt, C. Sandfort, A. Greilich, D. R. Yakovlev, D. Reuter, A. D. Wieck, and M. Bayer
Physical Review Letters 104, 036601 (2010), arXiv:0909.1592v1

Revealing the exciton fine structure in PbSe nanocrystal quantum dots using optical spectroscopy and high magnetic fields
R. D. Schaller, S. A. Crooker, D. A. Bussian, J. M. Pietryga, J. Joo, and V. I. Klimov
Physical Review Letters 105, 067403 (2010); arXiv:1006.5673v1

Interference-induced terahertz transparency in a semiconductor magneto-plasma
X. Wang, A. A. Belyanin, S. A. Crooker, D. M. Mittleman and J. Kono
Nature Physics 6, 126 (2010)

Optically-pumped NMR: Revealing spin-dependent Landau level transitions in GaAs
K. Ramaswamy, S. Mui, S. A. Crooker, X. Pan, G. D. Sanders, C. J. Stanton, and S. E. Hayes
Physical Review B 82, 085209 (2010)

Magneto-optical properties and charge-spin coupling in the molecular (2,3-dmpyH)(2)CuBr4 spin-ladder material
J. L. White, C. Lee, O. Gunaydin-Sen, L. C. Tung, H. M. Christen, Y.J. Wang, M. M. Turnbull, C. P. Landee, R. D. McDonald, S. A. Crooker, J. Singleton, M. H. Whangbo, J. L. Musfeldt
Physical Review B 81, 052407 (2010);

Bias-controlled sensitivity of ferromagnet-semiconductor electrical spin detectors
S. A. Crooker, E. S. Garlid, A. N. Chantis, D. L. Smith, K. S. M. Reddy, Q. O. Hu, T. Kondo, C. J. Palmstrom, and P. A. Crowell
Physical Review B Rapid Communications 80, 041305(R) (2009); arXiv:0809.1120v1

Spin noise of conduction electrons in n-type bulk GaAs (selected for Editor's Suggestion)
S. A. Crooker, L. Cheng, and D. L. Smith
Physical Review B 79, 035208 (2009); arXiv:0909.2680v1

Manifestation of Landau level effects in optically-pumped NMR of semi-insulating GaAs
Stacy Mui, Kannan Ramaswamy, Christopher J. Stanton, Scott A. Crooker and Sophia E. Hayes
Physical Chemistry and Chemical Physics 11, 7031 (2009)
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Tunable magnetic exchange interactions in Mn-doped inverted core-shell ZnSe/CdSe nanocrystals
D. A. Bussian, S. A. Crooker, M. Yin, M. Brynda, Al. L. Efros, and V. I. Klimov
Nature Materials 8, 35 (2009), arXiv.0811.1036v1

Anomalous circular polarization of magneto-photoluminescence from individual CdSe nanocrystals
H. Htoon, S. A. Crooker, M. Furis, S. Jeong, Al. L. Efros, and V. I. Klimov
Physical Review Letters 102, 017402 (2009). arXiv:0809.1116v1

Growth of magneto-optically active (ZnMn)Se nanowires
B. J. Cooley, T. E. Clark, B. Z. Liu, C. M. Eichfeld, E. C. Dickey, S. E. Mohney, S. A. Crooker, and N. Samarth
Nano Letters 9, 3142 (2009).

Magneto-optical spectroscopy of highly-aligned carbon nanotubes: Identifying the role of threading magnetic flux
J. Shaver, S. A. Crooker, J. A. Fagan, E. K. Hobbie, N. Ubrig, O. Portugall, V. Perebeinos, Ph. Avouris, and J. Kono
Physical Review B Rapid Communications 78, 081402(R) (2008).

Linearly-polarized 'fine-structure' of the bright exciton state in individual CdSe nanocrystal quantum dots
H. Htoon, M. Furis, S. A. Crooker, S. Jeong, and V. I. Klimov
Physical Review B 77, 035028 (2008).

Local Hanle-effect studies of spin drift and diffusion in n:GaAs epilayers and spin transport devices
M. Furis, D. L. Smith, S. Kos, E. S. Garlid, K. S. M. Reddy, C. J. Palmstrom, P. A. Crowell, and S. A. Crooker
New Journal of Physics 9, 347 (2007).

Electrical Detection of Spin Transport in Lateral Ferromagnet-Semiconductor Devices
X. Lou, C. Adelmann, S. A. Crooker, E. S. Garlid, J. Zhang, K. S. M. Reddy, S. D. Flexner, C. J. Palmstrom, and P. A. Crowell
Nature Physics 3, 197 (2007); cond-mat/0701021.

Tuning alloy disorder in diluted magnetic semiconductors in high fields to 89 tesla
S. A. Crooker and N. Samarth
Applied Physics Letters 90, 102109 (2007); cond-mat/0612332.

Optical and electrical spin injection and spin transport in hybrid Fe/GaAs devices
S. A. Crooker, M. Furis, X. Lou, C. Adelmann, D. L. Smith, C. J. Palmstrom, and P. A. Crowell
Journal of Applied Physics 101, 081716 (2007); cond-mat/0611729.

Modeling spin-polarized electron transport in semiconductors for spintronic applications
S. Kos, M. Hruska, S. A. Crooker, A. Saxena, and D. L. Smith
Computing in Science and Engineering 9, 46 (2007)

Spin noise spectroscopy to probe quantum states of ultracold fermionic atomic gases
B. Mihaila, S. A. Crooker, K. B. Blagoev, D. G. Rickel, P. B. Littlewood, and D. L. Smith
Physical Review A 74, 063608 (2006), cond-mat/0601011.

A quantitative study of spin noise spectroscopy in a classical gas of potassium-41 atoms
B. Mihaila, S. A. Crooker, K. B. Blagoev, D. G. Rickel, P. B. Littlewood, and D. L. Smith
Physical Review A 74, 043819 (2006), cond-mat/0604522.

Low temperature THz spectroscopy of n-InSb through a magnetic field driven metal-insulator transition
X. P. A. Gao, J. Y. Sohn, and S. A. Crooker
Applied Physics Letters 89, 122108 (2006), cond-mat/0605077.

Bias-dependent electron spin lifetimes in n-GaAs and the role of donor impact ionization
M. Furis, D. L. Smith, J. L. Reno, and S. A. Crooker
Applied Physics Letters 89, 102102 (2006); cond-mat/0605742.

Nonlinear optical transitions of GaAs/AlGaAs asymmetric double-well structures
E. H. Kim, Y. H. Shin, Y. Kim, S. J. Noh, C. H. Perry, J. A. Simmons, S. A. Crooker, and T. Takamasu
Applied Physics Letters 89, 32114 (2006);

Bright exciton fine structure and anisotropic exchange in CdSe nanocrystal quantum dots
M. Furis, T. Barrick, M. Petruska, H. Htoon, V. I. Klimov, and S. A. Crooker
Physical Review B Rapid Communications 73, 241313(R) (2006); cond-mat/0511567.

A tunable anomalous Hall effect in a non-ferromagnetic system
J. Cumings, L. S. Moore, H. T. Chou, K. C. Ku, G. Xiang, S. A. Crooker, N. Samarth, and D. Goldhaber-Gordon
Physical Review Letters 96, 196404 (2006); cond-mat/0512730.

Electrical detection of spin accumulation at a ferromagnet-semiconductor interface
X. Lou, C. Adelman, M. Furis, S. A. Crooker, C. J. Palmstrom, and P. A. Crowell
Physical Review Letters 96, 176603 (2006); cond-mat/0602096 .

Excitons in carbon nanotubes with broken time-reversal symmetry
S. Zaric, G. N. Ostojic, J. Shaver, J. Kono, O. Portugall, P.H. Frings, G. Rikken, M. Furis, S. A. Crooker, X. Wei, V. C. Moore, R. H. Hauge, and R. E. Smalley
Physical Review Letters 96, 016406 (2006); cond-mat/0509429.

Effects of strain, electric, and magnetic fields of lateral electron spin transport in semiconductor epilayers
M. Hruska, S. Kos, S. A. Crooker, A. Saxena, and D. L. Smith
Physical Review B 73, 075306 (2006); cond-mat/0511038.

Imaging Spin Transport in Lateral Ferromagnet/Semiconductor Structures
S. A. Crooker, M. Furis, X. Lou, C. Adelmann, D. L. Smith, C. J. Palmstrom, and P. A. Crowell
Science 309, 2191 (2005).

Imaging Spin Flows in Semiconductors Subject to Electric, Magnetic, and Strain Fields
S. A. Crooker and D. L. Smith
Physical Review Letters 94, 236601 (2005); cond-mat/0411461.

Time- and polarization-resolved optical spectroscopy of colloidal CdSe nanocrystal quantum dots in high magnetic fields
M. Furis, J. A. Hollingsworth, V. I. Klimov, and S. A. Crooker
Journal of Physical Chemistry B 109, 15332 (2005); cond-mat/0511676.

Magneto-optics of two-dimensional electron gases modified by strong Coulomb interactions in ZnSe quantum wells
D. Keller, D. R. Yakovlev, G.V. Astakhov, W. Ossau, S. A. Crooker, T. Slobodskyy, A. Waag, G. Schmidt, L. W. Molenkamp
Physical Review B 72, 235306 (2005); cond-mat/0509695.

Singlet and triplet trion states in high magnetic fields: Photoluminescence and reflectivity spectra of modulation-doped CdTe/Cd_0.7Mg_0.3Te quantum wells
D. Andronikov, V. Kochereshko, A. Platonov, T. Barrick, S. A. Crooker, and G. V. Karczewski
Physical Review B 72, 165339 (2005).

Spectroscopy of spontaneous spin noise as a probe of spin dynamics and magnetic resonance
S. A. Crooker, D. G. Rickel, A. V. Balatsky, and D. L. Smith
Nature 431, 49 (2004); cond-mat/0408107.

Definitive observation of the dark triplet ground state of charged excitons in high magnetic fields
G. V. Astakhov, D. R. Yakovlev, V. V. Rudenkov, P. C. M. Christianen, T. Barrick, S. A. Crooker, A. B. Dzyubenko, W. Ossau, J. C. Maan, G. Karczewski, and T. Wojtowicz
Phys. Rev. B Rapid Communications 71, 201312 (2005); cond-mat/0503693.

Role of Coulomb interactions in dark-bright magnetoexciton mixing in strained quantum wells
Y. D. Jho, F. V. Kyrychenko, J. Kono, X. Wei, S. A. Crooker, G. D. Sanders, D. H. Reitze, C. J. Stanton, and G. S. Solomon
Physical Review B 72, 45340 (2005); cond-mat/0410378.

Green luminescent zinc oxide films prepared by polymer-assisted deposition with rapid thermal process
Y. Lin, J. Xie, H. Wang, Y. Li, C. Chavez, S. Y. Lee, S. R. Foltyn, S. A. Crooker, A. K. Burrell, T. M. McCleskey, and Q. X. Jia
Thin Solid Films 492, 101 (2005).

Effects of chemical composition on the optical properties of ZnCdO thin films
S. Y. Lee, Y. Li, J. S. Lee, J. K. Lee, M. Nastasi, S. A. Crooker, Q. X. Jia, H. S. Kang, and J. S. Kang
Applied Physics Letters 85, 218 (2004).

Picosecond Energy Transfer in Quantum Dot Langmuir-Blodgett Nanoassemblies
M. Achermann, M. A. Petruska, S. A. Crooker, and V. I. Klimov
Journal of Physical Chemistry B 107, 13782 (2003); cond-mat/0310127.

Multiple temperature regimes of radiative decay in CdSe quantum dots: Intrinsic limits to the dark-exciton lifetime
S. A. Crooker, T. Barrick, J. Hollingsworth, and V. I. Klimov
Applied Physics Letters 82, 2793 (2003).

Spectrally-resolved dynamics of energy transfer in quantum dot assemblies: Towards engineered energy flows in artificial materials
S. A. Crooker, J. Hollingsworth, S. Tretiak, and V. I. Klimov
Physical Review Letters 89, 186802 (2002).

Fiber-coupled antennas for ultrafast coherent terahertz spectroscopy in low temperatures and high magnetic fields
S. A. Crooker
Review of Scientific Instruments 73, 3258 (2002).

Low-energy excitations in the magneto-optical response of alpha-NaV₂O₅
A. B. Sushkov, J. L. Musfeldt, X. Wei, S. A. Crooker, J. Jegoudez, A. Revcolevschi
Physical Review B 66, 054439 (2002).

Using electronic structure changes to map the H-T phase diagram of alpha-NaV₂O₅
A. B. Sushkov, J. L. Musfeldt, X. Wei, S. A. Crooker, J. Jegoudez, A. Revcolevschi
Physical Review B Rapid Communications 63, 220401 (2001).

Ultrafast carrier-relaxations dynamics in self-assembled InAs/GaAs quantum dots
D. A. Yarotski, R. D. Averitt, N. Negre, S. A. Crooker, A. J. Taylor, G. P. Donati, A. Stintz, L. F. Lester, and K. J. Malloy
Journal of the Optical Society of America B 19, 1480 (2002).

Binding energy of charged excitons in ZnSe-based quantum wells
G.V. Astakhov, D. R. Yakovlev, V. P. Kochereshko, W. Ossau, W. Faschinger, J. Puls, F. Henneberger, S.A. Crooker, Q. McCulloch, and D. Wolverson
Physical Review B 65, 165335 (2002); cond-mat/0112002.

Spin spectroscopy of dark excitons in CdSe quantum dots to 60 Tesla
E. Johnston-Halperin, D. D. Awschalom, S. A. Crooker, Al. L. Efros, M. Rosen, X. Peng, and A. P. Alivisatos
Physical Review B 63, 205309 (2001).

Stability of trions in strongly spin-polarized two-dimensional electron gases
S. A. Crooker, E. Johnston-Halperin, D. D. Awschalom, R. Knobel, and N. Samarth
Phys. Rev. B Rapid Communications 61, R16307 (2000).

Quasi-two-dimensional spin distributions in II-VI magnetic semiconductor heterostructures: Clustering and dimensionality
S. A. Crooker, N. Samarth, and D. D. Awschalom
Physical Review B 61, 1736 (2000).

Magnetic semiconductor quantum wells in high magnetic fields to 60 T: Photoluminescence linewidth annealing at magnetization steps
S. A. Crooker, D. G. Rickel, S. K. Lyo, N. Samarth, and D. D. Awschalom
Phys. Rev. B Rapid Communications 60, R2173 (1999).

Optical spin resonance and transverse spin relaxation in magnetic semiconductor quantum wells
S. A. Crooker, D. D. Awschalom, J. J. Baumberg, F. Flack, and N. Samarth
Physical Review B 56, 7574 (1997).

Femtosecond synchronization of two passively-modelocked Ti:sapphire lasers
S. A. Crooker, F. D. Betz, J. Levy, and D. D. Awschalom
Review of Scientific Instruments 67, 2068 (1996).

Terahertz spin precession and coherent transfer of angular momenta in magnetic quantum wells
S. A. Crooker, J. J. Baumberg, F. Flack, N. Samarth, and D. D. Awschalom
Physical Review Letters 77, 2814 (1996).

Time-resolved Faraday rotation spectroscopy of spin dynamics in digital magnetic heterostructures
S. A. Crooker, D. D. Awschalom, and N. Samarth
IEEE J. of Selected Topics in Quantum Electronics 1, 1082 (1995).

Enhanced Spin Interactions in Digital Magnetic Heterostructures
S. A. Crooker, D. A. Tulchinsky, J. Levy, D. D. Awschalom, R. Garcia, and N. Samarth
Physical Review Letters 75, 505 (1995).

Ultrafast Faraday spectroscopy in magnetic semiconductor quantum structures
J. J. Baumberg, S. A. Crooker, D. D. Awschalom, N. Samarth, H. Luo, and J. K. Furdyna
Physical Review B 50, 7689 (1994).

Selected Conference Publications

Tuning magnetic disorder in diluted magnetic semiconductors using high fields to 89 tesla, S. A. Crooker, N. Samarth, Int'l J. Modern Physics B 23, 2575 (2009) . High Magnetic Fields in Semiconductor Physics (HMF-18; Sao Pedro, Brazil, August 2008).

High field magneto-optical spectroscopy of highly aligned individual and ensemble single-walled carbon nanotubes, J. Shaver, A. Srivastava, J. Kono, S. A. Crooker, H. Htoon, V. I. Klimov, J. A. Fagan, E. K. Hobbie, N. Ubrig, O. Portugall, V. Perebeinos, P. H. Avouris, Int'l J. Modern Physics B 23, 2667 (2009) High Magnetic Fields in Semiconductor Physics (HMF-18; Sao Pedro, Brazil, August 2008).

Trion states in a dense 2D electron gas, VP Kochereshko, AA Klochikhin, SA Crooker, G Karczewski, J Kossut, Phys. Stat. Sol. (c) 6, 516 (2009) 9th Int'l Workshop on Nonlinear Optics and Excitation Kinetics in Semiconductors, May 26-29, 2008 Klink, Germany

Many body effects in the optical behavior of quantum well excitons, VP Kochereshko, DA Andronikov, AA Klochikhin, SA Crooker, G Karczewski, J Kossut Phys. Stat. Sol. (c) 5, 2404 (2008); 10th Int'l Conf. on Optics of Excitons in Confined Systems, Sept 10-13, 2007 Messina, Italy

Multielectron processes in the optics of two-dimensional excitons, VP Kochereshko, DA Andronikov, AA Klochikhin, SA Crooker, G Karczewski, J Kossut, AIP Conference Proceedings 893, 405 (2007); ICPS-28, Vienna Austria, July 24-28 2006.

Combined exciton-electron processes in two-dimensional electron gas, Andronikov, AA Klochikhin, GV Mikhailov, SA Crooker, G Karczewski, J Kossut, International Journal of Modern Physics B 21, 1535 (2007);

Behavior of excitons and trions in CdTe/CdMgTe quantum-well structures with variations in temperature, DA Andronikov, M Fehr, VP Kochereshko, SA Crooker, G Karczewski, Physics of the Solid State 49, 1567 (2007);

Symmetry of trion states in modulation-doped CdTe/CdMgTe nanostructures under a high magnetic field, P. Tronc, D. Andronikov, V. Kochereshko, S. A. Crooker, and G. Karczewski Physica Stat. Sol. (b) 244, 669 (2007);

Exciton localization and Stokes' shift in ZnCdO thin films depending on chemical composition, HS Kang, SH Lim, JW Kim, HW Chang, GH Kim, JH Kim, SY Lee, Y. Li, JS Lee, JK Lee, MA Nastasi, SA Crooker, QX Jia, Journal of Crystal Growth 287, 70 (2006);

Optical property and Stokes' shift of ZnCdO thin films depending on Cd content. HS Kang, JW Kim, JH Kim, SY Lee, Y Li, JS Lee, JK Lee, MA Nastasi, SA Crooker, QX Jia, Journal of Applied Physics 99, 66113 (2006).

Magneto-optical spectroscopy of carbon nanotubes (invited), S Zaric, GN Ostojic, J Shaver, J Kono, X Wei, M Furis, SA Crooker, O Portugall, PH Frings, G Rikken, VC Moore, RH Hauge, and RE Smalley, Physica E 29, 469 (2005); 1st International Symposium on Nanometer-scale Quantum Physics, Jan. 26-28, Tokyo.

Multielectron processes in the optics of two-dimensional excitons, VP Kochereshko, DA Andronikov, SA Crooker, G Karczewski, J Kossut, Phys. Stat. Sol. (c) 3, 2485 (2006) 8th Int'l Workshop on Nonlinear Optics and Excitation Kinetics In Semiconductors (NOEKS 8), Feb 20-24, 2006 Munster Germany.

Measuring random spin fluctuations for perturbation-free probes of spin dynamics and magnetic resonance (invited), SA Crooker, DG Rickel, AV Balatsky, and DL Smith, Proc. Soc. Photo-Opt. Inst. Eng. (SPIE) 5843, 58 (2005); SPIE Conf. on Fluctuations and Noise in Materials II; May 24-25, 2005; Austin, TX.

Exciton spin states in nanocrystal quantum dots revealed by spin-polarized resonant photoluminescence and Raman spectroscopy (invited), M Furis, T Barrick, P Robbins, SA Crooker, M Petruska, V Klimov, and AL Efros, International Journal of Modern Physics B 18, 3769-74 (2004); 16th Conf. on High Magnetic Fields in Semiconductor Physics (Semi-Mag 16), 2-6 Aug. 2004, Tallahassee.

Interband magneto-spectroscopy of a high-density two-dimensional electron gas in a strong in-plane magnetic field, YD Jho, X Wang, FV Kyrychenko, DH Reitze, CJ Stanton, J Kono, X Wei, SA Crooker, C Kadow, and AC Gossard, International Journal of Modern Physics B 18, 3831-4 (2004); 16th Conf. on High Magnetic Fields in Semiconductor Physics (Semi-Mag 16), 2-6 Aug. 2004, Tallahassee.

Time domain terahertz spectroscopy of the magnetic field induced metal-insulator transition in n:InSb, JY Sohn, XPA Gao, SA Crooker, AIP Conf. Proc. 772, 1216 (2005); 27th International Conference on the Physics of Semiconductors (ICPS-27); July 26-30, 2004; Flagstaff, AZ.

Excitons and trions in heavily doped QWs at high magnetic fields, V Kochereshko, D Andronikov, and G Karczewski, SA Crooker, AIP Conf. Proc. 772, 983-984 (2005); 27th International Conference on the Physics of Semiconductors (ICPS-27); July 26-30, 2004; Flagstaff, AZ.

Spin-polarized PL and Raman spectroscopy of nanocrystal quantum dots in high magnetic fields, M.Furis, PD Robbins, T Barrick, M. Petruska, VI Klimov, and SA Crooker, AIP Conf. Proc. 772, 709 (2005); 27th International Conference on the Physics of Semiconductors (ICPS-27); July 26-30, 2004; Flagstaff, AZ.

Excitons and trions in heavily doped QWs at high magnetic fields, Kochereshko, VP; Andronikov, DA; Karczewski, G; Crooker, SA, Physica Status Solidi C 2, 877 (2005); 4th International Conf. on Physics of Light-Matter Coupling in Nanostructures (PLMCN4); 2004; St. Petersburg, Russia.

Interband magnetoabsorption study of the shift of the Fermi energy of a 2DEG with an in-plane magnetic field, FV Kyrychenko, YD Jho, J Kono, SA Crooker, GD Sanders, DH Reitze, CJ Stanton, X Wei, C Kadow, AC Gossard, Physica E 22, 624 (2004); 15th International Conf. on Electronic Properties of 2D Systems (EP2DS-15), July 14-18 2003; Nara, Japan.

Identification of singlet and triplet states of negatively charged excitons in CdTe-based quantum wells, Astakhov, GV; Yakovlev, DR; Crooker, SA; Ossau, W.; Christianen, PCM; Rudenkov, VV; Karczewski, G.; Wojtowicz, T.; Kossut, J. Phys. Stat. Sol. C 1, 551-4 (2004); 8th Conference on Optics of Excitons in Confined Spaces, 15-17 Sept. 2003, Lecce, Italy.

Ultrafast Coherent Terahertz Spectroscopy in High Magnetic Fields and Directed Energy Flows in Quantum Dot Assemblies (invited), SA Crooker, T Barrick, JA Hollingsworth, and VI Klimov, Acta Physica Polonica A 104, 113 (2004); 32nd International School of Semicond. Compounds; June 2003; Jaszowiec, Poland.

Modulation of Energy Band Gap of ZnO Thin Films Grown by Pulsed Laser Deposition, SY Lee, Y Li, JS Lee, JK Lee, M Nastasi, SA Crooker, QX Jia, HS Kang, and JS Kang, MRS Proceedings 764, 413 (2003); New Applications for Wide-Bandgap Semiconductors; April 22-24, 2003, San Francisco, CA.

Singlet and triplet states of charged excitons in ZnSe-based QWs probed by high magnetic fields, DR Yakovlev, GV Astakhov, W Ossau, Q McCulloch, SA Crooker, and AB Dzyubenko, SPIE Proceedings 5023, 529 (2003); 10th International Symposium on Nanostructures; June 17-21 2002; St. Petersburg, Russia.

II-VI quantum wells with high carrier densities and in high magnetic fields, DR Yakovlev, GV Astakhov, W Ossau, SA Crooker, and A Waag, NATO Science Series II: 119, 137 (2003), NATO Adv. Res. Workshop on Optical Properties of 2D Systems with Interacting Electrons; June 2002; St. Petersburg, Russia.

Positively and negatively charged trions in ZnSe-based quantum wells, W Ossau, G Astakhov, DR Yakovlev, W Faschinger, VP Kochereshko, J Puls, F Henneberger, SA Crooker, Q McCulloch, and A Waag, NATO Science Series II 119, 41 (2003); NATO Adv. Res. Workshop on Optical Properties of 2D Systems with Interacting Electrons; June 2002; St. Petersburg, Russia.

Ultrafast coherent terahertz spectroscopy in high magnetic fields, SA Crooker and AJ Taylor, Int. J. of Modern Physics B 16, 3385 (2002); Physical Phenom. at High Mag. Fields IV, Oct. 19-25, 2001, Santa Fe, NM.

High magnetic field optical studies of charged exciton in CdTe 2D electron gases, N Negre, SA Crooker, A Wojs, and G Karczewski, International Journal of Modern Physics B 16, 2972 (2002),Physical Phenomena at High Magnetic Fields IV, Oct. 19-25, 2001, Santa Fe, NM.

Exciton diamagnetic shifts and magnetic field dependent linewidths in ordered and disordered InGaP alloys, Y Zhang, ED Jones, KK Bajaj, G Coli, SA Crooker, A Mascarenhas, and JM Olsen, MRS Proceedings 692, 313 (2001); Prog. in Semicond. Materials for Optoelectronic Applications; Nov 26-29, 2001; Boston, MA.

Trions in ZnSe-based quantum wells probed by 50 T magnetic fields, DR Yakovlev, GV Astakhov, W Ossau, SA Crooker, K Uchida, N Miura, A Waag, NA Gippius, AY Sivachenko, and AB Dzyubenko, Physica Status Solidi B 227, 353-63 (2001); Mini-Workshop on Trion Physics, 6-7 April 2001, Berlin, Germany.

High magnetic field optical studies of 2DEG in modulation-doped ZnSe quantum wells, W Ossau, DR Yakovlev, GV Astakhov, A Waag, CJ Meinig, HA Nickel, BD McCombe, and SA Crooker, Physica E 12, 512 (2002); 14th International Conf. on the Elec. Properties of 2-D Systems (EP2DS-14); Jul 30-Aug 3 2001, Prague, Czech Republic.

Optical spectroscopy of magnetic 2D electron gases at the Los Alamos pulsed magnetic field facility (invited), SA Crooker, DG Rickel, E Johnston-Halperin, DD Awschalom, R Knobel, N Samarth, SK Lyo, and A Efros, Physica B 298, 369 (2001); 14th International Conf. on High Magnetic Fields in Semiconductor Physics (Semi-Mag 14), Sept. 2000, Matsue, Japan.

Stability of charged excitons in strongly spin-polarized magnetic 2D electron gases, SA Crooker, E Johnston-Halperin, DD Awschalom, R Knobel, and N Samarth, Springer Proc. Phys. 87, 961-962 (2001), 25th International Conf. on the Physics of Semiconductors (ICPS-25); September 17-22, 2000; Osaka, Japan.

Spin-polarized quantum transport and magnetic field-dependent carrier density in magnetic two-dimensional electron gases, R Knobel, N Samarth, SA Crooker, and DD Awschalom, Physica E 6, 786-9 (2000), 13th International Conf. on the Electronic Properties of 2-D Systems (EP2DS-13); Aug 1-6, 1999; Ottawa, Canada.

Optical signatures from magnetic two-dimensional electron gases in magnetic fields to 60 T, SA Crooker, DG Rickel, IP Smorchkova, N Samarth, JM Kikkawa, and DD Awschalom, J. of Applied Physics 85, 5932 (1999), 43rd Annual Conference on Magnetism and Magnetic Materials, Nov 9-12, 1998, Miami, FL.

Spin transport and optically-probed coherence in magnetic semiconductor heterostructures, IP Smorchkova, FS Flack, N Samarth, JM Kikkawa, SA Crooker, and DD Awschalom, Physica B 249-251, 676 (1998), 12th International Conf. on the Elec. Properties of 2-D Systems (EP2DS-12), Sept. 22-26, 1997, Tokyo, Japan.

Growth dynamics and exciton localization in strained CdSe quantum structures, FS Flack, A Hunt, H Hennessey, N Samarth, J Levy, V Nikitin, SA Crooker, DD Awschalom, and M AlJassim, MRS Proceedings 417, 169-174 ; Optoelectronic Materials Symposium; Nov 28-30 1995; Boston, MA.

Ultrafast coherent transfer of spin angular momenta in magnetic semiconductor quantum wells, SA Crooker, JJ Baumberg, F Flack, N Samarth, and DD Awschalom, 23rd International Conference on the Physics of Semiconductors, p697, 21-26 July 1996, Berlin, Germany.

Spin beats and magnetic dynamics in II-VI quantum structures, J. J. Baumberg, S. A. Crooker, D. D. Awschalom, N. Samarth, Materials Science Forum 182-184, 429-434 (1995), Proceedings of the 4th International Workshop on Semimagnetic (Diluted Magnetic) Semiconductors; Sep 26-28 1994; Linz, Austria

Selected Invited Presentations

"Listening" to spin and magnetization noise, Physics Colloquium, Texas A&M University (October 20, 2022)

Many-body excitons in monolayer semiconductor [plenary], PQE-2022, January 10-14, 2022, Snowbird, UT)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, OECS-17 [virtual] August 30 - September 2, 2021)

Spontaneous valley polarization of interacting carriers in a monolayer semiconductor, MRS Spring Meeting [virtual] April 19, 2021)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, Physics Colloquium, University of Buffalo [virtual] April 15, 2021)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, CM Seminar, Rutgers University [virtual] April 6, 2021)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, CM Seminar, UC San Diego [virtual] (January 13, 2021)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, MAS-APS Meeting [virtual] (December 2020)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, MRS Fall Meeting [virtual] (December 2020)

"Listening" to spin and magnetization noise, Purdue University [virtual] (November 11, 2020)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, EDS seminar, Cornell University [virtual] (November 20, 2020)

Listening to spin noise at (and beyond?) the standard quantum limit, IEEE QCE20 [virtual] (October 2020)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, Engineering Physics Seminar, Montreal Polytechnique (December 2019)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, 2D Materials Center Seminar, Penn State University (October 2019)

"Listening" to spin and magnetization noise, Department of Physics Colloquium, Penn State University (October 2019)

Electrons, holes, and excitons in monolayer semiconductors: Insights from (really) high magnetic fields, Condensed Matter Phyiscs Seminar, University of Minnesota (September 2019)

"Listening" to spin and magnetization noise, Department of Physics Colloquium, University of Minnesota (September 2019)

Thermodynamic valley noise and Rydberg magneto-excitons in monolayer semiconductors, FOPS-2019 (Banff, Canada August 4-9, 2019)

Monolayer Semiconductors I: Optical properties, excitons, & (the importance of) dielectric screening, Quantum Science Summer School (Penn State University, June 10-14, 2019)

Monolayer Semiconductors II: Valley dynamics and valley noise, Quantum Science Summer School (Penn State University, June 10-14, 2019)

"Valley noise" & valley correlations in monolayer semiconductors , Strongly Correlated Quantum Materials (Santa Fe, NM, April 29- May 3 2019)

"Valley noise" and Rydberg magneto-excitons in monolayer semiconductors , LASSP seminar, Cornell University (October 2018)

Long-lived spin and valley dynamics in monolayer semiconductors, Physics and Applications of Spin Phenomena in Solids (PASPS-2018; Linz, Austria, August 5-9, 2018)

Monolayer semiconductors in high magnetic fields: Excitons, dielectric screening, & Rydberg states, International Conference on Semiconductor Physics (Montpellier, France, July 29-August 3, 2018)

"Listening" to the spin noise of electrons and holes in semiconductors, Symposium 50 years of Optical Orientation in Semiconductors (Paris, France, June 18-19, 2018)

Excitons and dielectric screening effects in 2D semiconductors: Insight from high magnetic fields, 2D Materials Beyond Graphene (Penn State University, May 9-11, 2018)

Light, spin, and magnetization in magnetically-doped nanocrystals, WINDS-2017, Hapuna Beach, HI (Nov 26-30, 2017)

Excitons, dielectric screening, & Rydberg excitons in 2D semiconductors: Insight from high B fields, FOPS-2017, Skamania Lodge, WA (Aug 27-30, 2017)

Excitons, electrons & holes in 2D semiconductors: Dielectric screening & spin/valley dynamics, 2D Materials Workshop, Ohio State University, 5-9 June (2017)

Spin/valley dynamics of resident electrons and holes in 2D semiconductors, MIT Valleytronics Workshop, MIT, 22-23 August (2017)

Spin & valley dynamics of electrons & holes in monolayer semiconductors, GRAPHENE-2017, Barcelona, Spain (Mar. 28-31, 2017)

Excitons, electrons & holes in 2D semiconductors: Dielectric screening & spin/valley dynamics, APS March Meeting, New Orleans, LA (Mar. 12-17, 2017)

Spin relaxation & coherence of electrons in atomically-thin semiconductors, Fall MRS meeting, Boston, MA (Nov. 27-Dec. 1, 2016)

Spin relaxation & coherence of electrons in monolayer transition-metal dichalcogenides, Rocky Mountain EPR Symposium, Breckenridge, CO (July 17-22, 2016)

Spin relaxation & coherence of electrons in monolayer transition-metal dichalcogenides, Gordon Research Conference on 2D Materials, Mt. Holyoke, MA (June 5-9, 2016)

Spin relaxation & coherence of electrons in monolayer transition-metal dichalcogenides, PQE-2016, Snowbird, UT (January 3-7, 2016)

Giant internal magnetic fields due to thermodynamic spin fluctuations in magnetically-doped nanocrystals , BES/AMOS Program review, Gaithersburg, MD (October 26-28, 2015)

Long-lived spin relaxation & spin coherence of resident electrons in MoS2, Fundamental Optical Processes in Semiconductors (FOPS-2015), Breckenridge, CO (August 2-6, 2015)

Optically-induced persistent magnetization in oxygen-deficient strontium titanate, American Physical Society March Meeting 2015, San Antonio, TX (March 2-6, 2015)

Optically-induced persistent magnetization in oxygen-deficient strontium titanate, Physics and Chemistry of Semiconductor Interfaces (PCSI-42), Snowbird, UT (January 18-22, 2015)

Optically-induced persistent magnetization in oxygen-deficient strontium titanate, High Magnetic Fields in Semiconductor Physics (HMF-21), Panama City, FL (August 3-8, 2014)

Optically-induced persistent magnetization in oxygen-deficient strontium titanate, MESO-CNLS, Santa Fe, NM (March 10-15, 2014)

Optically-induced persistent magnetization in oxygen-deficient strontium titanate [contributed], PASPS-VIII, Washington DC, (July 28-31, 2014)

Optically-induced persistent magnetization in oxygen-deficient strontium titanate, SPIE Optics and Photonics Conference, San Diego, CA (August 25-29, 2013)

Listening to the spin noise of electrons and holes in semiconductor quantum dots, Int'l Conference on Spin-Optronics (ICSO-2013), Toulouse, France (June 10-14, 2013)

Magneto-optical spectroscopy of organic interfaces, Organic Solar Cells, Santa Fe, NM (May 6-8, 2013)

Listening to the spin noise of holes coupled to nuclear spin baths in semiconductor quantum dots, SPIE Photonics West, San Francisco, CA (February 4-7, 2013)

Long-lived photomagnetization in copper-doped ZnSe nanocrystals, SPIE Optics and Photonics Conference, San Diego, CA; (August 12-17, 2012)

Magnetic textures in quantum magnets in nondestructive 100+ Tesla fields, High Magnetic Fields in Semiconductor Physics (HMF-20), Chamonix, France (July 22-27, 2012)

"Listening" to the spin noise of electrons and holes in semiconductors, 4th Int'l Nano-MRI Conference, Ascona, Switzerland, (July 22-27, 2012)

"Listening" to the spin noise of electrons and holes in semiconductors, 41st "Jaszowiec" International School and Conference on the Physics of Semiconductors, Krynica, (Poland June 10, 2012)

"Listening" to the spin noise of electrons and holes in semiconductors, Department of Physics, Texas A&M University, College Station, TX (March 23, 2012)

"Listening" to the spin noise of electrons and holes in semiconductors, Department of Physics, Rice University, Houston, TX (March 22, 2012)

"Listening" to the spin noise of electrons and holes in semiconductor quantum structures, Department of Physics, Ohio State University, Columbus, OH (January 19, 2012)

"Listening" to the spin noise of electrons and holes in semiconductor quantum structures, Oregon Center for Optics, University of Oregon, Eugene, OR (November 7, 2011)

"Listening" to the spin noise of electrons and holes in semiconductor quantum structures, Argonne National Laboratory, Argonne, IL (October 26, 2011)

"Listening" to the spin noise of electrons and holes in semiconductor quantum structures, 2011 SPIE Optics and Photonics, San Diego, CA (August 20-23, 2011)

"Listening" to the spin noise of electrons and holes in InGaAs quantum dots, 2011 APS March Meeting, Dallas, TX (March 20-25, 2011)

Tunable coupling of electronic and magnetic degrees of freedom in colloidal nanocrystals, 2010 MRS Fall Meeting, Boston (November 28-December 3, 2010)

"Listening" to the spin noise of electrons and holes in semiconductors, Department of Physics Colloquium, University of Buffalo, Buffalo NY, October 7, 2010.

"Listening" to the spin noise of electrons and holes in semiconductors, Department of Electrical Engineering Colloquium, University of Rochester, Rochester NY, October 6, 2010.

"Listening" to the spin noise of electrons and holes in semiconductors, Laboratoire National des Champs Magnetiques Intenses, Toulouse, France, September 20 (2010)

"Listening" to the spin noise of electrons and holes in semiconductors, High Magnetic Field Laboratory, Grenoble, France, September 22 (2010)

Imaging spin injection and spin transport in semiconductors, DPG Physics School on Nano-Spintronics, Bad Honnef, Germany, September 15 (2010)

"Listening" to the spin noise of electrons and holes in semiconductors, DPG Physics School on Nano-Spintronics, Bad Honnef, Germany, September 17 (2010)

"Listening" to the spin noise of electrons and holes in semiconductors, 6^th Int'l Conf. on Phys. and Appl. of Spin-Related Phenomena in Semiconductors (PASPS-6), Tokyo, Japan, (August 1-4, 2010)

Spin physics and exciton fine structure in semiconductor nanocrystals, Center for Advanced Solar Photophysics, Los Alamos, NM, March 8 (2010)

"Listening" to the spin noise of electrons and holes in semiconductors, Condensed Matter Seminar, UC San Diego (February 3, 2010)

Efficient electrical spin detection and optical spin noise spectroscopy, Seminar, Tohoku University, Sendai, Japan (December 9, 2009)

Optical spectroscopy of magnetic semiconductors in pulsed fields to 89 tesla, 6th IMR International Symposium on High Magnetic Field Spin Science in 100T, Sendai, Japan (Dec. 8, 2009)

Imaging the injection and flow of spin-polarized electrons in semiconductors, Seminar, Technical University of Dortmund, Dortmund, Germany (October 7, 2009)

Toward efficient electrical spin detection in lateral spin-transport devices, Symposium on Spin Manipulation in Solid-State Systems, Wurzburg, Germany (October 8-9, 2009)

Tunable magnetic exchange interactions in magnetically-doped core/shell nanocrystals, Excited State Processes in Electronic and Bio-nanomaterials (ESP-2009), Santa Fe, New Mexico (June 29-July 2, 2009)

Toward efficient electrical spin detection in lateral spin-transport devices, Spins in Organic Semiconductors (SPINOS-2009), Salt Lake City, Utah (Feb. 4-7, 2009)

Imaging spin injection and transport in semiconductor spintronic devices, Optics Seminar, University of Oregon, Eugene OR (Feb. 2, 2009)

Exciton fine structure in semiconductor nanocrystals using high-field and single-dot spectroscopy, DOE/BES program review, AMOS-2008, Warrington, VA (September 14-17, 2008)

Tuning magnetic disorder in diluted magnetic semiconductors using high fields to 89 T, High Mag. Fields in Semiconductor Physics (HMF-18), Sao Pedro, Brazil (August 3-8, 2008)

Imaging spin injection and spin transport in semiconductors, CLEO/QUELS 2008, San Jose, CA (May, 2008)

Imaging the drift and diffusion of optically- and electrically-injected spins in semiconductors, APS March Meeting 2008, New Orleans, LA (March, 2008)

Imaging spin injection in ferromagnet/semiconductor spin transport devices, Experimental Condensed Matter Physics Seminar, Ohio State University (February 8, 2008)

Spin injection, transport, and imaging in epitaxial Fe/GaAs devices, 35th Conf. on the Physics and Chemistry of Semiconductor Interfaces (PCSI-35) (January 13-17, 2008, Santa Fe, NM)

Imaging spin flows in Fe/GaAs electrical spin injection and detection, 2007 Materials Research Society (MRS) Fall Meeting (Boston, November 26-27, 2007)

Tuning the sign and sensitivity of Fe/GaAs electrical spin detectors [selected for contributed talk], SPINTECH-IV, (Maui, June 20-22, 2007)

Imaging spin injection and spin transport in lateral Fe/GaAs devices, Optical Properties of Low Dimensional Semiconductors (OPLDS-2007) (Ottawa, May 2007)

Imaging the injection and flow of spin polarized electrons in ferromagnet-semiconductor devices, Condensed Matter Seminar, Naval Research Laboratory (March 29, 2007)

Imaging spin injection in semiconductors, Condensed Matter Physics Seminar, Dept. of Physics, University of Pennsylvania (March 28, 2007)

Imaging the injection and flow of spin polarized electrons in ferromagnet-semiconductor devices, Condensed Matter Seminar, Princeton University (March 26, 2007)

Imaging the injection and flow of spin polarized electrons in ferromagnet-semiconductor devices, Physics, Chemistry & Nanosciences Colloquium, Sandia National Laboratory, (March 21, 2007)

Imaging the injection and flow of spin polarized electrons in ferromagnet-semiconductor devices, Condensed Matter Seminar, Dept. of Physics, UC San Diego (Dec. 2006)

Imaging electrical spin injection in lateral ferromagnet-semiconductor devices, AVS 53rd International Symposium, (November 12-17, 2006, San Francisco, CA)

Imaging spin transport in lateral ferromagnet/semiconductor structures, 28th International Conference on the Physics of Semiconductors (ICPS-28) (July 2006, Vienna, Austria).

Imaging electrical spin injection and spin flow in ferromagnet-semiconductor devices (Plenary), 14th International Symp. on Nanostructures: Physics and Technology (St. Petersburg, Russia, June 2006).

Spectroscopy of spontaneous spin noise in atomic and solid state systems, Gordon Research Conference on Ultrafast Phenomena in Correlated Systems, February 2006 (Buellton, CA).

Imaging spin transport in lateral ferromagnet-semiconductor devices, Nanoscience Seminar, UC Riverside, January 2006.

Imaging the flow of spin-polarized electrons in semiconductors, Department of Physics Colloquium, UC Santa Cruz, January 2006.

Imaging electrical spin injection and spin flow in ferromagnet/semiconductor devices, Solid State and Optics Seminar, Yale University, October 5, 2005.

Imaging the flow of electron spins in semiconductors in the presence of electric, magnetic and strain fields, 16th International Conf. on Elec. Prop. of 2-D Systems (EP2DS-16), July 10-15, 2005, Albuquerque, NM.

Imaging spin flows in semiconductors in the presence of electric, magnetic, and strain fields, Exciton-Electron Interactions in Semiconductor Nanostructures, May 29-June 2, 2005, Bad Honnef, Germany.

Imaging spin flows in semiconductors in the presence of electric, magnetic, and strain fields, High Magnetic Field Laboratory, May 27, 2005, Radboud University, Nijmegen, The Netherlands.

Measuring random spin fluctuations for perturbation-free probes of spin dynamics and magnetic resonance, 3rd SPIE International Symposium on Fluctuations and Noise, May 24-25, 2005, Austin, TX.

Spectroscopy of spontaneous spin noise for probes of spin dynamics and magnetic resonance, APS March Meeting 2005 (Los Angeles, CA).

Imaging spin flows in semiconductors, 35th Winter Colloquium on the Physics of Quantum Electronics (PQE-2005), Jan 2-6, 2005, Snowbird, UT.

Spin noise spectroscopy as a probe of magnetic resonance, Condensed, Atomic, and Molecular Physics Seminar, Pennsylvania State University, December 7, 2004.

Engineered energy flows in nanocrystals quantum dot assemblies, 34th Winter Colloquium on the Physics of Quantum Electronics (PQE-2004), Jan 4-8, 2004, Snowbird, UT.

High magnetic field terahertz spectroscopy of semiconductors and superconductors, 11th IEEE International Conf. on Terahertz Electronics (THz 2003), September 24-26, 2003, Sendai, Japan.

Terahertz spectroscopy in high magnetic fields and directed energy flows in quantum dot assemblies, 32nd International School of Semiconducting Compounds, May 30-June 6, 2003, Jaszowiec, Poland.

II-VI Heterostructures, Quantum Dots, and THz spectroscopy in high magnetic fields to 60 T, University of Wuerzburg , May 28, 2003.

Towards engineered energy flows in quantum dot assemblies, APS March Meeting 2003 (Austin, TX).

Dynamics of Exciton Transfer in Semiconductor Quantum-Dot Assemblies, Optical Society of America 18th Laser Science Conference (LS-XVIII), Sept 29-Oct 3, 2002, Orlando, FL.

Optical spectroscopy of magnetic 2-D electron gases at the Los Alamos pulsed magnetic field facility, 14th International Conf. on High Magnetic Fields in Semiconductor Physics, Sept 24-29, 2000, Matsue, Japan.

Static and time-resolved optical spectroscopies in pulsed fields: Magnetic 2-D electron gases to 60 Tesla, APS March Meeting 1999 (Atlanta, GA).

Collaborators

Xavier Marie, Bernhard Urbaszek, and Cedric Robert (INSA-Toulouse).
Xiaodong Xu (University of Washington).
Peter Schiffer (Yale University).
Chris Leighton (University of Minnesota).
Sergio Brovelli (University of Milan - Bicocca).
Peter Armitage (Johns Hopkins University).
Hao Zeng (University of Buffalo).
Victor Klimov and his Softmatter Nanotechnology team (Chemistry Division, Los Alamos National Laboratory).
Berend (Berry) Jonker and Kathleen McCreary (Naval Research Laboratory).
Jun Lou (Rice University).
Junichiro Kono (Rice University).
Nikolai Sinitsyn and Cristiano Nisoli (Theoretical Division, Los Alamos National Laboratory).
Manfred Bayer and Dmitri Yakovlev, (Technical University of Dortmund, Germany).