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Related papers: Spin Transition in the Half-Filled Landau Level

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We demonstrate a way to polarize and detect nuclear spin in a gate-defined quantum point contact operating at high Landau levels. Resistively-detected Nuclear Magnetic Resonance (RDNMR) can be achieved up to the $5$th Landau level and at a…

Mesoscale and Nanoscale Physics · Physics 2018-06-06 M. H. Fauzi , A. Noorhidayati , M. F. Sahdan , K. Sato , K. Nagase , Y. Hirayama

We observe nuclear magnetic resonance (NMR) in the fractional quantum Hall regime at Landau level filling factor $\nu=2/3$ from simultaneous measurement of longitudinal resistance and photoluminescence (PL). The dynamic nuclear spin…

Mesoscale and Nanoscale Physics · Physics 2016-08-11 K. Akiba , K. Nagase , Y. Hirayama

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

Hyperfine interactions between electron and nuclear spins in the quantum Hall regime provide powerful means for manipulation and detection of nuclear spins. In this work we demonstrate that significant changes in nuclear spin polarization…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Y. Q. Li , V. Umansky , K. von Klitzing , J. H. Smet

The behavior of relativistic particles in an electric and/or magnetic field is considered in the general case when the direction of propagation may differ from the direction of the field. A special attention is paid to the spin splitting…

Quantum Physics · Physics 2013-05-01 Tihomir G. Tenev , Nikolay V. Vitanov

NMR measurements of the electron spin polarization have been performed on a 2D electron system at and around half-filled lowest Landau level. Comparing the magnetic field and the temperature dependence of the spin polarization to models of…

Mesoscale and Nanoscale Physics · Physics 2016-08-16 N. Freytag , M. Horvatić , C. Berthier , M. Shayegan , L. P. Lévy

Resistively detected nuclear magnetic resonance is used to measure the Knight shift of the As nuclei and determine the electron spin polarization of the fractional quantum Hall states of the second Landau level. We show that the 5/2 state…

Strongly Correlated Electrons · Physics 2015-06-03 M. Stern , B. A. Piot , Y. Vardi , V. Umansky , P. Plochocka , D. K. Maude , I. Bar-Joseph

The average electron spin-polarization $\cal P$ of two-dimensional electron gas confined in $\rm GaAs/GaAlAs$ multiple quantum-wells was measured by nuclear magnetic resonance (NMR) near the fractional quantum Hall state with filling factor…

Mesoscale and Nanoscale Physics · Physics 2019-08-17 N. Freytag , Y. Tokunaga , M. Horvatic , C. Berthier , M. Shayegan , L. Levy

The Knight shift and the nuclear spin-lattice relaxation rate 1/T1 of Ga-71 nuclei are measured in GaAs quantum wells at Landau level filling factor nu = 1/2 using optically pumped NMR. The temperature dependences of these data are compared…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. E. Dementyev , N. N. Kuzma , P. Khandelwal , S. E. Barrett , L. N. Pfeiffer , K. W. West

We report electrical transport measurements in a tilted magnetic field on a high-mobility two-dimensional electron system confined at the MgZnO/ZnO heterointerface. The observation of multiple crossing events of spin-resolved Landau levels…

Mesoscale and Nanoscale Physics · Physics 2015-06-23 D. Maryenko , J. Falson , Y. Kozuka , A. Tsukazaki , M. Kawasaki

Polarization-resolved magneto-luminescence, together with simultaneous magneto-transport measurements, have been performed on a two-dimensional electron gas (2DEG) confined in CdTe quantum well in order to determine the spin-splitting of…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 J. Kunc , K. Kowalik , F. J. Teran , P. Plochocka , B. A. Piot , D. K. Maude , M. Potemski , V. Kolkovsky , G. Karczewski , T. Wojtowicz

Dynamic nuclear polarization transfers spin polarization from electrons to nuclei. We have achieved this by a new method, simultaneously exciting transitions of electronic and nuclear spins. The efficiency of this technique improves with…

Quantum Physics · Physics 2008-09-11 G. W. Morley , K. Porfyrakis , A. Ardavan , J. van Tol

A resistively detected NMR technique was used to probe the two-dimensional electron gas in a GaAs/AlGaAs quantum well. The spin-lattice relaxation rate $(1/T_{1})$ was extracted at near complete filling of the first Landau level by…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 G. Gervais , H. L. Stormer , D. C. Tsui , P. L. Kuhns , W. G. Moulton , A. P. Reyes , L. N. Pfeiffer , K. W. Baldwin , K. W. West

The study of nuclear magnetic resonance and nuclear spin-lattice relaxation was conducted in an asymmetrically doped to $n\sim1.8\times10^{11}$ cm$^{-2}$ 16 nm AlAs quantum well grown in the $[001]$-direction. Dynamic polarization of…

Mesoscale and Nanoscale Physics · Physics 2016-12-22 A. V. Shchepetilnikov , D. D. Frolov , Yu. A. Nefyodov , I. V. Kukushkin , D. S. Smirnov , L. Tiemann , C. Reichl , W. Dietsche , W. Wegscheider

We develop a theory of the half-filled Landau level which shows that it is a two-component fluid. One of the components has spin up and the other spin down so that the electron-spin resonance can occur. The 1/3 filled level is fully spin…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Keshav N. Shrivastava

Nuclear electric resonance (NER) is based on nuclear magnetic resonance mediated by spatial oscillations of electron spin domains excited by a radio frequency (RF) electric field, and it allows us to investigate the spatial distribution of…

Mesoscale and Nanoscale Physics · Physics 2012-10-25 S. Watanabe , G. Igarashi , N. Kumada , Y. Hirayama

We investigate interactions between electrons and nuclear spins by using the resistance (Rxx) peak which develops near filling factor n = 2/3 as a probe. By temporarily tuning n to a different value, ntemp, with a gate, the Rxx peak is…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 K. Hashimoto , K. Muraki , T. Saku , Y. Hirayama

Dirac semimetals provide a new platform for the quantum Hall effect at low magnetic fields. In the presence of strong spin-orbit coupling, a spin-split Landau level is expected to enhance the bulk quasiparticle excitation. Here we report…

Strongly Correlated Electrons · Physics 2026-03-02 Masashi Kumazaki , Azimjon Temurjonov , Yukihiro Watanabe , Taku Matsuhita , Yoshiaki Kobayashi , Yasuhiro Shimizu

The spin degree of freedom in quantum phases of the second Landau level is probed by resonant light scattering. The long wavelength spin wave, which monitors the degree of spin polarization, is at the Zeeman energy in the fully…

Strongly Correlated Electrons · Physics 2015-03-17 Trevor D. Rhone , Jun Yan , Yann Gallais , Aron Pinczuk , Loren Pfeiffer , Ken West

We consider the effect of interactions on electrons confined to two dimensions at Landau level filling $\nu=2$, with the specific aim to determine the range of parameters where the fully polarized state is stable. We calculate the charge…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 K. Park , J. K. Jain
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