English
Related papers

Related papers: Electrical spin injection into p-doped quantum dot…

200 papers

Spin-polarized light-emitting diodes (spin-LEDs) convert the electronic spin information to photon circular polarization, offering potential applications including spin amplification, optical communications, and advanced imaging. The…

Mesoscale and Nanoscale Physics · Physics 2024-08-12 Jianchen Dang , Tongyao Wu , Shuohua Yan , Kenji Watanabe , Takashi Taniguchi , Hechang Lei , Xiao-Xiao Zhang

Spin-polarized electron photoemission has been studied for GaAs/GaAs$_{1-x}$P$_x$ strained superlattice cathodes grown by gas-source molecular beam epitaxy. The superlattice structural parameters are systematically varied to optimize the…

Instrumentation and Detectors · Physics 2009-11-10 T. Maruyama , D. -A. Luh , A. Brachmann , J. E. Clendenin , E. L. Garwin , S. Harvey , J. Jiang , R. E. Kirby , C. Y. Prescott , R. Prepost , A. M. Moy

Quantum spin Hall insulators, recently realized in HgTe/(Hg,Cd)Te quantum wells, support topologically protected, linearly dispersing edge states with spin-momentum locking. A local magnetic exchange field can open a gap for the edge…

Mesoscale and Nanoscale Physics · Physics 2013-05-30 Carsten Timm

We present a numerical study of magnetic phases of the 2D electron gas near freezing. The calculations are performed by diffusion Monte Carlo in the fixed node approximation. At variance with the 3D case we find no evidence for the…

Strongly Correlated Electrons · Physics 2009-10-31 D. Varsano , S. Moroni , G. Senatore

Magnetic noise of atomic nuclear spins is a major problem for solid state spin qubits. Highly-polarized nuclei would not only overcome this obstacle, but also make nuclear spins a useful quantum information resource. However, achieving…

We investigate the dynamic polarization of nuclear spins in a nominally undoped GaAs/Al$_{0.35}$Ga$_{0.65}$As quantum well using two complementary experimental approaches: time-resolved Kerr rotation and optical orientation measurements of…

Mesoscale and Nanoscale Physics · Physics 2025-12-24 M. Kotur , D. Kudlacik , N. E. Kopteva , E. Kirstein , D. R. Yakovlev , K. V. Kavokin , M. Bayer

We have studied the current through a carbon nanotube quantum dot with one ferromagnetic and one normal-metal lead. For the values of gate voltage at which the normal lead is resonant with the single available non-degenerate energy level on…

Mesoscale and Nanoscale Physics · Physics 2008-08-20 Christopher A. Merchant , Nina Markovic

We inject spin-polarized electrons from an Fe/MgO tunnel barrier contact into n-type Ge(001) substrates with electron densities 2e16 < n < 8e17 cm-3, and electrically detect the resulting spin accumulation using three-terminal Hanle…

Materials Science · Physics 2012-02-20 A. T. Hanbicki , S. -. F. Cheng , R. Goswami , O. M. J. van `t Erve , B. T. Jonker

We report the successful extraction of spin polarized current from the organic-based room temperature ferrimagnetic semiconductor V[TCNE]x (x~2, TCNE: tetracyanoethylene; TC ~ 400 K, EG ~ 0.5 eV, s ~ 10-2 S/cm) and its subsequent injection…

Materials Science · Physics 2015-05-19 Lei Fang , K. Deniz Bozdag , Chia-Yi Chen , P. A. Truitt , A. J. Epstein , E. Johnston-Halperin

Spin-dependent tunneling through an indirect bandgap barrier like the GaAs/AlAs/GaAs heterostructure along [001] direction is studied by the tight-binding method. The tunneling is characterized by the proportionality of the Dresselhaus…

Materials Science · Physics 2009-07-01 Titus Sandu , Athanasios Chantis , Radu Iftimie

Topological insulators (TIs) are an unusual phase of quantum matter with nontrivial spin-momentum locked topological surface states (TSS). The electrical detection of spin-momentum locking of the TSS in 3D TIs has been lacking till very…

Mesoscale and Nanoscale Physics · Physics 2015-09-29 Jifa Tian , Ireneusz Miotkowski , Seokmin Hong , Yong P. Chen

The hyperfine interaction of an electron with nuclei in the annealed self-assembled InAs/GaAs quantum dots is theoretically analyzed. For this purpose, the annealing process, and energy structure of the quantum dots are numerically modeled.…

Other Condensed Matter · Physics 2010-08-05 M. Yu. Petrov , I. V. Ignatiev , S. V. Poltavtsev , A. Greilich , A. Bauschulte , D. R. Yakovlev , M. Bayer

We investigate effect of a step-doping profile on the spin injection from a ferromagnetic metal contact into a semiconductor quantum well (QW) in spin FETs using a Monte Carlo model. The considered scheme uses a heavily doped layer at the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Min Shen , Semion Saikin , Ming-Cheng Cheng

We demonstrate that efficient optical pumping of nuclear spins in semiconductor quantum dots (QDs) can be achieved by resonant pumping of optically "forbidden" transitions. This process corresponds to one-to-one conversion of a photon…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 E. A. Chekhovich , M. N. Makhonin , K. V. Kavokin , A. B. Krysa , M. S. Skolnick , A. I. Tartakovskii

In this paper we show that it is possible to switch the spin polarization of the photocurrent signal obtained from a single self-assembled quantum dot photodiode under the effect of elliptically polarized light by just increasing the light…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 J. M. Villas-Boas , Sergio E. Ulloa , A. O. Govorov

The dynamics of the coupled electron-nuclear spin system is studied in an ensemble of singly-charged (In,Ga)As/GaAs quantum dots (QDs) using periodic optical excitation at 1 GHz repetition rate. In combination with the electron-nuclei…

Mesoscale and Nanoscale Physics · Physics 2021-08-11 E. Evers , N. E. Kopteva , I. A. Yugova , D. R. Yakovlev , M. Bayer , A. Greilich

Using a `standard' NMR spin-echo technique we determined the spin polarization of two-dimensional electrons, confined to GaAs quantum wells, from the hyperfine shift of Ga nuclei in the wells. Concentrating on the temperature and magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. Melinte , N. Freytag , M. Horvatic , C. Berthier , L. P. Levy , V. Bayot , M. Shayegan

While microscopic laws of physics are invariant under the reversal of the arrow of time, the transport of energy and information in most devices is an irreversible process. It is this irreversibility that leads to intrinsic dissipations in…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Shuichi Murakami , Naoto Nagaosa , Shou-Cheng Zhang

We report millisecond-range spin memory of resident electrons in an ensemble of InP quantum dots (QDs) under a small magnetic field of 0.1 T applied along the optical excitation axis at temperatures up to about 5 K. A pump-probe…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Bipul Pal , Michio Ikezawa , Yasuaki Masumoto , Ivan V. Ignatiev

In this contribution, we investigated the spin coherence of high-mobility dense two-dimensional electron gases confined in multilayer systems. The dynamics of optically-induced spin polarization was experimentally studied employing the…

Mesoscale and Nanoscale Physics · Physics 2018-06-11 S. Ullah , G. M. Gusev , A. K. Bakarov , F. G. G. Hernandez