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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…

By using highly time-resolved spectroscopy with an alternative {\sigma}+/{\sigma} - laser pulse modulation technique, we are able to measure the fast buildup and decay times of the dynamical nuclear spin polarization (DNSP) at 5 K for a…

Mesoscale and Nanoscale Physics · Physics 2015-06-03 X. M. Dou , B. Q. Sun , D. S. Jiang , H. Q. Ni , Z. C. Niu

A highly asymmetric dynamic nuclear spin pumping is observed in a single self assembled InGaAs quantum dot subject to resonant optical pumping of the neutral exciton transition leading to a large maximum polarization of 54%. This dynamic…

Mesoscale and Nanoscale Physics · Physics 2010-09-30 F. Klotz , V. Jovanov , J. Kierig , E. C. Clark , M. Bichler , G. Abstreiter , M. S. Brandt , J. J. Finley , H. Schwager , G. Giedke

We present an experimental study of the dynamics underlying the buildup and decay of dynamical nuclear spin polarization in a single semiconductor quantum dot. Our experiment shows that the nuclei can be polarized on a time scale of a few…

Optics · Physics 2007-08-02 P. Maletinsky , A. Badolato , A. Imamoglu

The periodic optical orientation of electron spins in (In,Ga)As/GaAs quantum dots leads to the formation of electron spin precession modes about an external magnetic field which are resonant with the pumping periodicity. As the electron…

Mesoscale and Nanoscale Physics · Physics 2019-08-15 E. Evers , V. V. Belykh , N. E. Kopteva , I. A. Yugova , A. Greilich , D. R. Yakovlev , D. Reuter , A. D. Wieck , M. Bayer

We investigate the dynamic nuclear polarization process by frequently injecting polarized electron spins into a quantum dot. Due to the suppression of the direct dipolar and indirect electron-mediated nuclear spin interactions, by the…

Mesoscale and Nanoscale Physics · Physics 2016-07-26 Na Wu , Wenkui Ding , Anqi Shi , Wenxian Zhang

Nuclear spin polarization can be pumped into spin-blocked quantum dots by multiple Landau- Zener passages through singlet-triplet anticrossings. By numerical simulations of realistic systems including approximately $10^7$ nuclear spins…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Arne Brataas , Emmanuel I. Rashba

Early experiments on spin-blockaded double quantum dots revealed surprising robust, large-amplitude current oscillations in the presence of a static (dc) source-drain bias [see e.g. K. Ono, S. Tarucha, Phys. Rev. Lett. 92, 256803 (2004)].…

Mesoscale and Nanoscale Physics · Physics 2013-05-02 M. S. Rudner , L. S. Levitov

Nuclear-spin diffusion in double quantum wells (QWs) is examined by using dynamic nuclear polarization (DNP) at a Landau level filling factor $\nu=2/3$ spin phase transition (SPT). The longitudinal resistance increases during the DNP of one…

Mesoscale and Nanoscale Physics · Physics 2015-04-01 T. Hatano , W. Kume , S. Watanabe , K. Akiba , K. Nagase , Y. Hirayama

We proposed and demonstrated that the nuclear spins of the host lattice in GaAs double quantum dots can be strongly polarized in either of two opposite directions, parallel or antiparallel to an external magnetic field. The direction is…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Ryo Takahashi , Kimitoshi Kono , Seigo Tarucha , Keiji Ono

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

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 control of nuclear spins in quantum dots is essential to explore their many-body dynamics and exploit their prospects for quantum information processing. We present a unique combination of dynamic nuclear spin polarization and…

Mesoscale and Nanoscale Physics · Physics 2015-12-16 Florian Forster , Max Mühlbacher , Dieter Schuh , Werner Wegscheider , Geza Giedke , Stefan Ludwig

We investigate in micro-photoluminescence experiments the dynamical nuclear polarization in individual InGaAs quantum dots. Experiments carried out in an applied magnetic field of 2T show that the nuclear polarization achieved through the…

Other Condensed Matter · Physics 2009-11-13 B. Urbaszek , P. -F. Braun , X. Marie , O. Krebs , A. Lemaitre , P. Voisin , T. Amand

We theoretically investigate the controlled dynamic polarization of lattice nuclear spins in GaAs double quantum dots containing two electrons. Three regimes of long-term dynamics are identified, including the build up of a large difference…

Mesoscale and Nanoscale Physics · Physics 2012-11-07 M. Gullans , J. J. Krich , J. M. Taylor , H. Bluhm , B. I. Halperin , C. M. Marcus , M. Stopa , A. Yacoby , M. D. Lukin

We report on the dynamic nuclear polarization of a single charge-tunable self-assembled InAs/GaAs quantum dot in a longitudinal magnetic field of $\sim$0.2T. The hyperfine interaction between the optically oriented electron and nuclei spins…

We study the optically induced spin polarization, spin dephasing and diffusion in several high-mobility two-dimensional electron systems, which are embedded in GaAs quantum wells grown on (110)-oriented substrates. The experimental…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 R. Voelkl , M. Schwemmer , M. Griesbeck , S. A. Tarasenko , D. Schuh , W. Wegscheider , C. Schueller , T. Korn

Hyperfine coupling of electron spins to nuclear spins is studied for a GaAs-based double quantum dot in the spin blockade regime where the electron conduction is mostly blocked by Pauli effect unless the electron spin state in the double…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Keiji Ono , Seigo Tarucha

The nature of the nano-scale environment presents a major challenge for solid-state implementation of spin-based qubits. In this work, a single electron spin in an optically pumped nanometer-sized III-V semiconductor quantum dot is used to…

We study the polarisation dependence of the homogeneously broadened nuclear spin resonance in a crystal. We employ a combinatorial method to restrict the nuclear states to a fixed polarisation and show that the centre of the resonance is…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 O. Tsyplyatyev , D. M. Whittaker
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