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Related papers: Spontaneous spin polarization in quantum point con…

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We propose a novel scheme to efficiently polarize and manipulate the electron spin in a quantum dot. This scheme is based on the spin-orbit interaction and it possesses following advantages: (1) The direction and the strength of the spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Qing-feng Sun , X. C. Xie

We report circular-to-linear and linear-to-circular conversion of optical polarization by semiconductor quantum dots. The polarization conversion occurs under continuous wave excitation in absence of any magnetic field. The effect…

We polarize nuclear spins in a GaAs double quantum dot by controlling two-electron spin states near the anti-crossing of the singlet (S) and m_S=+1 triplet (T+) using pulsed gates. An initialized S state is cyclically brought into resonance…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 J. R. Petta , J. M. Taylor , A. C. Johnson , A. Yacoby , M. D. Lukin , C. M. Marcus , M. P. Hanson , A. C. Gossard

We investigate the dynamic nuclear polarization from the hyperfine interaction between nonequilibrium electronic spins and nuclear spins coupled to them in semiconductor nanostructures. We derive the time and position dependence of the…

Materials Science · Physics 2007-05-23 Ionel Tifrea , Michael E. Flatte

Zero length quantum wires (or point contacts) exhibit unexplained conductance structure close to 0.7 X 2e^2/h in the absence of an applied magnetic field. We have studied the density- and temperature-dependent conductance of…

Strongly Correlated Electrons · Physics 2007-05-23 D. J. Reilly , G. R. Facer , A. S. Dzurak , B. E. Kane , R. G. Clark , P. J. Stiles , J. L. O'Brien , N. E. Lumpkin , L. N. Pfeiffer , K. W. West

Model independent formulae are derived for the polarizations and spin correlations of protons in the final state of $pp \to pp\omega $, taking into consideration all the six threshold partial wave amplitudes $f_1, ..., f_6$ covering $Ss,…

Nuclear Theory · Physics 2010-04-06 G. Ramachandran , Venkataraya , J. balasubramanyam

We exploit ferromagnetic imprinting to create complex laterally defined regions of nuclear spin polarization in lithographically patterned MnAs/GaAs epilayers grown by molecular beam epitaxy (MBE). A time-resolved Kerr rotation microscope…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 J. Stephens , R. K. Kawakami , J. Berezovsky , M. Hanson , D. P. Shepherd , A. C. Gossard , D. D. Awschalom

A non-equilibrium Green function formalism (NEGF) is used to study the conductance of a side-gated quantum point contact (QPC) in the presence of lateral spin-orbit coupling (LSOC). A small difference of bias voltage between the two side…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 J. Wan , M. Cahay , P. Debray , R. Newrock

A non-equilibrium Green's function formalism is used to study in detail the ballistic conductance of asymmetrically biased side-gated quantum point contacts (QPCs) in the presence of lateral spin-orbit coupling and electron-electron…

Mesoscale and Nanoscale Physics · Physics 2010-10-01 J. Wan , M. Cahay , P. Debray , R. S. Newrock

We investigate theoretically the polarization properties of the quantum dot's optical emission from chiral photonic crystal structures made of achiral materials in the absence of external magnetic field at room temperature. The mirror…

We theoretically investigate dynamic nuclear spin polarization in a self-assembled quantum dot pumped optically by two laser beams. With the assumption that a noncollinear interaction between the hole spin and nuclear spins leads to nuclear…

Mesoscale and Nanoscale Physics · Physics 2013-06-07 Xiao-Feng Shi

We measure the statistical polarization of quadrupolar nuclear spins in a sub-micrometer (0.6 um^3) particle of GaAs using magnetic resonance force microscopy. The crystalline sample is cut out of a GaAs wafer and attached to a…

Mesoscale and Nanoscale Physics · Physics 2016-11-25 Fei Xue , D. P. Weber , P. Peddibhotla , M. Poggio

We develop a theoretical description of transport through quantum dots connected to reservoirs via spin-polarized ballistic contacts. Rate equations account for spin accumulation inside the dot, electron-electron interactions, and…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Eugene G. Mishchenko , Arne Brataas , Yaroslav Tserkovnyak

Spontaneous nuclear polarization is predicted in double quantum dots in the spin-blocked electron transport regime. The polarization results from an instability of the zero-polarization state when singlet and triplet electron energy levels…

Mesoscale and Nanoscale Physics · Physics 2010-08-23 M. S. Rudner , L. S. Levitov

Polarized antiprotons can be produced in a storage ring by spin--dependent interaction in a purely electron--polarized hydrogen gas target. The polarizing process is based on spin transfer from the polarized electrons of the target atoms to…

We characterize spin-polarized lasing in a two-dimensional photonic lattice fabricated from a GaAs/InGaAs semiconductor microcavity sample. The lattice is defined by a staggered arrangement of rounded rectangular micrometric mesas that…

A novel spin orientation mechanism - dynamic electron spin polarization has been recently suggested in Phys. Rev. Lett. $\mathbf{125}$, 156801 (2020). It takes place for unpolarized optical excitation in weak magnetic fields of the order of…

Mesoscale and Nanoscale Physics · Physics 2021-09-15 T. S. Shamirzaev , A. V. Shumilin , D. S. Smirnov , J. Rautert , D. R. Yakovlev , M. Bayer

Spin-echo instruments are typically used to measure diffusive processes and the dynamics and motion in samples on ps and ns timescales. A key aspect of the spin-echo technique is to determine the polarisation of a particle beam. We present…

Materials Science · Physics 2018-02-05 Anton Tamtögl , Benjamin Davey , David J. Ward , Andrew P. Jardine , John Ellis , William Allison

We describe a method for precise estimation of the polarization of a mesoscopic spin ensemble by using its coupling to a single two-level system. Our approach requires a minimal number of measurements on the two-level system for a given…

Quantum Physics · Physics 2009-11-11 G. Giedke , J. M. Taylor , D. D'Alessandro , M. D. Lukin , A. Imamoglu

A double-quantum-dot coupled to electrodes with spin-dependent splitting of chemical potentials (spin bias) is investigated theoretically by means of the Green's functions formalism. By applying a large spin bias, the quantum spin in a…

Mesoscale and Nanoscale Physics · Physics 2008-06-16 Hai-Zhou Lu , Shun-Qing Shen