English
Related papers

Related papers: Electrically-Driven Reverse Overhauser Pumping of …

200 papers

We investigate the electric manipulation of a single electron spin in a single gate-defined quantum dot. We observe that so-far neglected differences between the hyperfine and spin-orbit mediated electric dipole spin resonance conditions…

Quantum Physics · Physics 2013-06-27 M. Shafiei , K. C. Nowack , C. Reichl , W. Wegscheider , L. M. K. Vandersypen

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

Nuclear spins are polarized electrically in a breakdown regime of an odd-integer quantum Hall effect (QHE). Electron excitation to the upper Landau subband with the opposite spin polarity flips nuclear spins through the hyperfine…

Mesoscale and Nanoscale Physics · Physics 2008-07-04 M. Kawamura , H. Takahashi , S. Masubuchi , Y. Hashimoto , S. Katsumoto , K. Hamaya , T. Machida

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 observe multiple stable states of nuclear polarization in a double quantum dot under conditions of electron spin resonance. The stable states can be understood within an elaborated theoretical rate equation model for the polarization in…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 J. Danon , I. T. Vink , F. H. L. Koppens , K. C. Nowack , L. M. K. Vandersypen , Yu. V. Nazarov

We theoretically study the nuclear spin dynamics driven by electron transport and hyperfine interaction in an electrically-defined double quantum dot (DQD) in the Pauli-blockade regime. We derive a master-equation-based framework and show…

Mesoscale and Nanoscale Physics · Physics 2014-06-03 Martin J. A. Schuetz , Eric M. Kessler , Lieven M. K. Vandersypen , J. Ignacio Cirac , Geza Giedke

We consider spin rotations in single- and two-electron quantum dots that are driven by external AC electric field with two mechanisms that couple the electron spatial motion and the spin degree of freedom: the spin-orbit interaction and a…

Mesoscale and Nanoscale Physics · Physics 2013-10-08 E. N. Osika , B. Szafran , M. P. Nowak

The spin dynamics of positively (X$^{+}$) and negatively (X$^{-}$) charged excitons in InP/In$_{0.48}$Ga$_{0.52}$P quantum dots subject to a magnetic field is studied. We find that a characteristic feature of the system under study is the…

Mesoscale and Nanoscale Physics · Physics 2019-12-18 S. V. Nekrasov , I. A. Akimov , Yu. G. Kusrayev , D. R. Yakovlev , M. Bayer

We report electrical control of the spin polarization of InAs/GaAs self-assembled quantum dots (QDs) at room temperature. This is achieved by electrical injection of spin-polarized electrons from an Fe Schottky contact. The circular…

We study a mechanism by which nuclear hyperpolarization due to the polarization transfer from a microwave-pulse-controlled electron spin is suppressed. From analytical and numerical calculations of the unitary dynamics of multiple nuclear…

Quantum Physics · Physics 2024-03-12 Kento Sasaki , Eisuke Abe

Dynamic Nuclear Polarization (DNP) presently stands as the preferred strategy to enhance the sensitivity of nuclear magnetic resonance measurements, but its application relies on the use of high-frequency microwave to manipulate electron…

Mesoscale and Nanoscale Physics · Physics 2022-02-02 Carlos A. Meriles , Pablo R. Zangara

We demonstrate methods to locally control the spin rotation of moving electrons in a GaAs channel. The Larmor frequency of optically-injected spins is modulated when the spins are dragged through a region of spin-polarized nuclei created at…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 M. E. Nowakowski , G. D. Fuchs , S. Mack , N. Samarth , D. D. Awschalom

Hyperfine interaction of electron spins with nuclear spins, in coupled double quantum dots is studied. Results of successive electron spin measurements exhibit bunching due to correlations induced via the nuclear spins. Further nuclear…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Ozgur Cakir , Toshihide Takagahara

Nuclear spin coherence and relaxation dynamics of all constituent isotopes of an n-doped CdTe/(Cd,Mg)Te quantum well structure are studied employing optically detected nuclear magnetic resonance. Using time-resolved pump-probe Faraday…

Mesoscale and Nanoscale Physics · Physics 2019-04-04 E. Evers , T. Kazimierczuk , F. Mertens , D. R. Yakovlev , G. Karczewski , T. Wojtowicz , J. Kossut , M. Bayer , A. Greilich

The photoluminescence polarizations of (In,Ga)As/GaAs quantum dots annealed at different temperatures are studied as a function of external magnetic field (Hanle curves). In these dependencies, remarkable resonant features appear due to…

We show that by illuminating an InGaAs/GaAs self-assembled quantum dot with circularly polarized light, the nuclei of atoms constituting the dot can be driven into a bistable regime, in which either a threshold-like enhancement or reduction…

A quasi-classical theoretical description of polarization and relaxation of nuclear spins in a quantum dot with one resident electron is developed for arbitrary mechanisms of electron spin polarization. The dependence of the…

Strongly Correlated Electrons · Physics 2015-05-13 I. A. Merkulov , G. Alvarez , D. R. Yakovlev , T. C. Schulthess

Control of electron spin decoherence in contact with a mesoscopic bath of many interacting nuclear spins in an InAs quantum dot is studied by solving the coupled quantum dynamics. The nuclear spin bath, because of its bifurcated evolution…

Mesoscale and Nanoscale Physics · Physics 2011-11-09 Ren-Bao Liu , Wang Yao , L. J. Sham

We study the influence of narrowed distributions of the nuclear Overhauser field on the decoherence of a central electron spin in quantum dots. We describe the spin dynamics in quantum dots by the central spin model. We use analytic…

Mesoscale and Nanoscale Physics · Physics 2016-09-16 Lars B. Gravert , Peter Lorenz , Carsten Nase , Joachim Stolze , Götz S. Uhrig

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
‹ Prev 1 4 5 6 7 8 10 Next ›