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Related papers: Spontaneous spin polarization in quantum point con…

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In zero magnetic field, conductance measurements of clean one-dimensional (1D) constrictions defined in GaAs/AlGaAs heterostructures show twenty-six quantized ballistic plateaux, as well as a structure close to $0.7(2e^2/h)$. In an in-plane…

Condensed Matter · Physics 2009-10-28 K. J. Thomas , J. T. Nicholls , M. Y. Simmons , M. Pepper , D. R. Mace , D. A. Ritchie

The strongly interacting system created in ultrarelativistic nuclear collisions behaves almost as an ideal fluid with rich patterns of the velocity field exhibiting strong vortical structure. Vorticity of the fluid, via spin-orbit coupling,…

Nuclear Experiment · Physics 2024-10-30 Takafumi Niida , Sergei A. Voloshin

In this paper, I present a simple method of obtaining spin-polarised current from a QPC with a large Rashba interaction. The origin of this spin polarisation is the adiabatic evolution of spin "up" of the first QPC sub-band, into spin…

Mesoscale and Nanoscale Physics · Physics 2018-11-29 Samuel Bladwell

Nuclear spin polarization dynamics are measured in optically pumped individual GaAs/AlGaAs interface quantum dots by detecting the time-dependence of the Overhauser shift in photoluminescence (PL) spectra. Long nuclear polarization decay…

We suggest a new spin orientation mechanism for localized electrons: $dynamic~electron~spin~polarization~provided~by~nuclear~spin~fluctuations$. The angular momentum for the electrons is gained from the nuclear spin system via the hyperfine…

Mesoscale and Nanoscale Physics · Physics 2020-10-14 D. S. Smirnov , T. S. Shamirzaev , D. R. Yakovlev , M. Bayer

Measurements and modeling of electron spin transport and dynamics are used to characterize hyperfine interactions in Fe/GaAs devices with $n$-GaAs channels. Ga and As nuclei are polarized by electrically injected electron spins, and the…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 M. K. Chan , Q. O. Hu , J. Zhang , T. Kondo , C. J. Palmstrøm , P. A. Crowell

We study repeated (noncontinuous) measurements on the electron spin in a quantum dot and find that the measurement technique may lead to a different met$ or mechanism to realize nuclear spin polarization. While it may be used in any case,…

Quantum Physics · Physics 2011-07-28 Lian-Ao Wu

A self-consistent calculation of the electronic properties of GaAlAs:Mn magnetic semiconductor quantum well structures is performed including the Hartree term and the sp-d exchange interaction with the Mn magnetic moments. The spin…

Materials Science · Physics 2009-10-31 A. Ghazali , I. C. da Cunha Lima , M. A. Boselli

We have studied polariton spin dynamics in a GaAs/AlGaAs microcavity by means of polarization- and time-resolved photoluminescence spectroscopy as a function of excitation density and normal mode splitting. The experiments reveal a novel…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. D. Martin , L. Vina , J. K. Son , E. E. Mendez

Pure spin currents are measured in micron-wide channels of GaAs two-dimensional electron gas (2DEG). Spins are injected and detected using quantum point contacts, which become spin polarized at high magnetic field. High sensitivity to the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 S. M. Frolov , A. Venkatesan , W. Yu , W. Wegscheider , J. A. Folk

There is controversy as to whether a one-dimensional (1D) electron gas can spin polarise in the absence of a magnetic field. Together with a simple model, we present conductance measurements on ultra low-disorder quantum wires supportive of…

Strongly Correlated Electrons · Physics 2007-05-23 D. J. Reilly , T. M. Buehler , J. L. O'Brien , A. R. Hamilton , A. S. Dzurak , R. G. Clark , B. E. Kane , L. N. Pfeiffer , K. W. West

A ring structure fabricated from GaAs is used to achieve interference of the net spin polarization of conduction band electrons. Optically polarized spins are split into two packets by passing through two arms of the ring in the diffusive…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Y. K. Kato , R. C. Myers , A. C. Gossard , D. D. Awschalom

A quantum dot spin LED provides a test of carrier spin injection into a qubit, as well as a means of analyzing carrier spin injection in general and local spin polarization. The polarization of the observed light is, however, significantly…

Condensed Matter · Physics 2009-11-10 C. E. Pryor , M. E. Flatté

We demonstrate a new method for electrical manipulation of nuclear spins utilizing dynamic nuclear polarization induced by quantum Hall effect breakdown. Nuclear spins are polarized and detected through the hyperfine interaction between a…

Mesoscale and Nanoscale Physics · Physics 2009-04-17 Minoru Kawamura , Hiroyuki Takahashi , Yoshiaki Hashimoto , Shingo Katsumoto , Tomoki Machida

We report conductance measurements of a ballistic one-dimensional (1D) wire defined in the lower two-dimensional electron gas of a GaAs/AlGaAs double quantum well. At low temperatures there is an additional structure at $0.7(2e^2/h)$ in the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 K. J. Thomas , J. T. Nicholls , M. Pepper , W. R. Tribe , M. Y. Simmons , D. A. Ritchie

We propose and demonstrate a new method to probe local spin polarization in semiconductor micro devices at low and zero magnetic fields. By connecting a single-lead quantum dot to a semiconductor micro device and monitoring electron…

Mesoscale and Nanoscale Physics · Physics 2012-09-18 Tomohiro Otsuka , Yuuki Sugihara , Jun Yoneda , Shingo Katsumoto , Seigo Tarucha

We study the optically pumped nuclear spin polarization in a single GaAs/AlGaAs quantum well in the quantum Hall system. We apply resistive detection via the contact hyperfine interaction, which provides high sensitivity and selectivity, to…

Mesoscale and Nanoscale Physics · Physics 2013-06-24 K. Akiba , T. Yuge , S. Kanasugi , K. Nagase , Y. Hirayama

We have studied quantum wires using the Green's function technique and the density-functional theory, calculating the electronic structure and the conductance. All the numerics are implemented using the finite-element method with a…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Paula Havu , Martti Puska , Risto Nieminen , Ville Havu

We use point contact Andreev reflection spin spectroscopy to measure the transport spin polarization of MnAs epitaxial films grown on (001) GaAs. By analyzing both the temperature dependence of the contact resistance and the phonon spectra…

Strongly Correlated Electrons · Physics 2009-11-10 R. Panguluri , G. Tsoi , B. Nadgorny , S. H. Chun , N. Samarth , I. I. Mazin

We devise an approach to measure the polarization of nuclear spins via conductance measurements. Specifically, we study the combined effect of external magnetic field, nuclear spin polarization, and Rashba spin-orbit interaction on the…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 James A. Nesteroff , Yuriy V. Pershin , Vladimir Privman