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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

The spin of a confined electron, when oriented originally in some direction, will lose memory of that orientation after some time. Physical mechanisms leading to this relaxation of spin memory typically involve either coupling of the…

Mesoscale and Nanoscale Physics · Physics 2013-07-24 A. C. Johnson , J. R. Petta , J. M. Taylor , A. Yacoby , M. D. Lukin , C. M. Marcus , M. P. Hanson , A. C. Gossard

Thermal motion of the flux lines (FL) gives rise to fluctuating magnetic fields. These dynamic fields couple to the nuclei in the sample and relax the nuclear spins. Based on a model of harmonic fluctuations, we provide a theoretical…

Condensed Matter · Physics 2009-10-22 Lei Xing , Yia-Chung Chang

Experimental investigation of nuclear spin effects on the electron spin polarization in singly negatively charged InP quantum dots is reported. Pump-probe photoluminescence measurements of electron spin relaxation in the microsecond…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Bipul Pal , Sergey Yu. Verbin , Ivan V. Ignatiev , Michio Ikezawa , Yasuaki Masumoto

We report our NMR study of the spin excitations in the quasi-one dimensional (1D) $S=1/2$ quantum magnet CH$_3$NH$_3$Cu(HCOO)$_3$ lying in the 1D-3D dimensional crossover regime with Dzyaloshinskii-Moriya(DM) interactions. Above $T_N$, the…

Strongly Correlated Electrons · Physics 2019-09-19 Long Ma , Z. Wang , L. Hu , Z. Qu , N. Hao , Li Pi

We report tilted-field transport measurements in the quantum-Hall regime in an InAs/In_0.75Ga_0.25As/In_0.75Al_0.25As quantum well. We observe anti-crossings of spin-split Landau levels, which suggest a mixing of spin states at Landau level…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 W. Desrat , F. Giazotto , V. Pellegrini , M. Governale , F. Beltram , F. Capotondi , G. Biasiol , L. Sorba

We report on transport measurements of dual-gated, single-layer graphene devices in the quantum Hall regime, allowing for independent control of the filling factors in adjoining regions. Progress in device quality allows us to study…

Mesoscale and Nanoscale Physics · Physics 2014-05-15 F. Amet , J. R. Wiliams , K. Watanabe , T. Taniguchi , D. Goldhaber-Gordon

The evolution of the electron spin dynamics as consequence of carrier delocalization in $n$-type GaAs is investigated by the recently developed extended pump-probe Kerr/Faraday rotation spectroscopy. We find that isolated electrons…

Mesoscale and Nanoscale Physics · Physics 2017-12-11 V. V. Belykh , K. V. Kavokin , D. R. Yakovlev , M. Bayer

We perform a full microscopic investigation on the spin relaxation in $n$-type (001) GaAs quantum wells with Al$_{0.4}$Ga$_{0.6}$As barrier due to the D'yakonov-perel' mechanism from nearly 20 K to the room temperature by constructing and…

Materials Science · Physics 2007-05-23 J. Zhou , J. L. Cheng , M. W. Wu

We measure the chemical potential jump across the fractional gap in the low-temperature limit in the two-dimensional electron system of GaAs/AlGaAs single heterojunctions. In the fully spin-polarized regime, the gap for filling factor…

Strongly Correlated Electrons · Physics 2007-09-03 V. S. Khrapai , A. A. Shashkin , M. G. Trokina , V. T. Dolgopolov , V. Pellegrini , F. Beltram , G. Biasiol , L. Sorba

We study the interaction-enhanced spin gaps in the two-dimensional electron gas confined in GaAs/AlGaAs single heterojunctions subjected to weak magnetic fields. The values are obtained from the chemical potential jumps measured by…

Strongly Correlated Electrons · Physics 2007-05-23 V. S. Khrapai , A. A. Shashkin , E. L. Shangina , V. Pellegrini , F. Beltram , G. Biasiol , L. Sorba

The spin-lattice relaxation rate $T_{1}^{-1}$ and NMR spectra of $^1$H in single crystal molecular magnets of Fe8 have been measured down to 15 mK. The relaxation rate $T_1^{-1}$ shows a strong temperature dependence down to 400 mK. The…

Condensed Matter · Physics 2009-11-07 Miki Ueda , Satoru Maegawa , Susumu Kitagawa

By solving the kinetic spin Bloch equations, we study the time evolution of the transient spin grating, whose spin polarization varies periodically in real space, confined in (001) GaAs quantum wells. With this study we can investigate the…

Materials Science · Physics 2008-03-23 M. Q. Weng , M. W. Wu , H. L. Cui

The proton nuclear spin-lattice relaxation rate 1/T1 has been measured as a function of temperature and magnetic field (up to 15 T) in the molecular magnetic ring Fe10. Striking enhancement of 1/T1 is observed around magnetic field values…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 M. -H. Julien , Z. H. Jang , A. Lascialfari , F. Borsa , M. Horvatic , A. Caneschi , D. Gatteschi

We present an experimental and theoretical study of the longitudinal electron spin relaxation ($T_1$) of shallow donors in the direct band-gap semiconductor ZnO. $T_1$ is measured via resonant excitation of the Ga donor-bound exciton. $T_1$…

This study investigated the formation and relaxation dynamics of nuclear spin polarization in three Al$_x$Ga$_{1-x}$As bulk samples with different aluminum concentrations $x$ of 0.00, 0.05, and 0.15. The time-resolved Kerr rotation…

Materials Science · Physics 2026-02-20 A. Shen , J. Chen , R. Kaji , S. Yamamoto , H. Sasakura , T. Uemura , S. Adachi

We present a numerical study of spin relaxation in a semiclassical electron ensemble in a large ballistic quantum dot. The dot is defined in a GaAs/AlGaAs heterojunction system with a two-dimensional electron gas, and relaxation occurs due…

Mesoscale and Nanoscale Physics · Physics 2008-04-21 E. J. Koop , B. J. van Wees , C. H. van der Wal

We report single-crystal 51V NMR studies on volborthite Cu3V2O7(OH)2 2H2O, which is regarded as a quasi-two-dimensional frustrated magnet with competing ferromagnetic and antiferromagnetic interactions. In the 1/3 magnetization plateau…

The nuclear spin-lattice relaxation time ($T_1$) of lanthanum and aluminum nuclei in a single crystal of lanthanum aluminate doped with neodymium ions is studied to estimate the feasibility of the dynamically polarized lanthanum target…

Instrumentation and Detectors · Physics 2021-10-27 K. Ishizaki , H. Hotta , I. Ide , M. Iinuma , T. Iwata , M. Kitaguchi , H. Kohri , D. Miura , Y. Miyachi , T. Ohta , H. M. Shimizu , H. Yoshikawa , M. Yosoi

The tilting angular dependence of the energy gap was measured in the bilayer quantum Hall state at the Landau level filling $\nu=1$ by changing the density imbalance between the two layers. The observed gap behavior shows a continuous…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 D. Terasawa , M. Morino , K. Nakada , S. Kozumi , A. Sawada , Z. F. Ezawa , N. Kumada , K. Muraki , Y. Hirayama , T. Saku