Resistive detection of optically pumped nuclear polarization with spin phase transition peak at Landau level filling factor 2/3

2011 ◽  
Vol 99 (11) ◽  
pp. 112106 ◽  
Author(s):  
K. Akiba ◽  
S. Kanasugi ◽  
K. Nagase ◽  
Y. Hirayama
Keyword(s):  
Phase Transition ◽  
Landau Level ◽  
Nuclear Polarization ◽  
Filling Factor ◽  
Optically Pumped

SPATIAL DISTRIBUTION OF KNIGHT SHIFT AROUND QUANTUM HALL EDGE CHANNELS USING RESISTIVELY-DETECTED NMR

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1440-1444
Author(s):  
S. MASUBUCHI ◽  
K. HAMAYA ◽  
T. MACHIDA
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Spatial Distribution ◽  
Knight Shift ◽  
Nuclear Polarization ◽  
Filling Factor ◽  
Quantum Hall ◽  
Electron Spin Polarization ◽  
Local Electron ◽  
Nmr Spectrum ◽  
Edge Channel

We develop a method for studying spatial distribution of the Knight shift using resistively-detected nuclear magnetic resonance (NMR) in an AlGaAs/GaAs quantum Hall device. By controlling the position of the dynamic nuclear polarization with the side-gate voltage, the spatial distribution of the NMR spectrum is investigated in a vicinity of quantum Hall edge channels. The value of Knight shift gradually changes in the region where the local Landau-level filling factor is between ν = 1 and ν = 2, implying that the change of the local electron spin polarization is detected in the edge channel.

Nuclear Polarization ofHe3Gas by Metastability Exchange with Optically Pumped MetastableHe3Atoms

1962 ◽  
Vol 8 (11) ◽  
pp. 439-442 ◽  
Author(s):  
G. K. Walters ◽  
F. D. Colegrove ◽  
L. D. Schearer
Keyword(s):  
Nuclear Polarization ◽  
Optically Pumped

Optically pumped NMR: Revealing spin-dependent Landau level transitions in GaAs

2010 ◽  
Vol 82 (8) ◽  
Author(s):  
K. Ramaswamy ◽  
S. Mui ◽  
S. A. Crooker ◽  
X. Pan ◽  
G. D. Sanders ◽  
...  
Keyword(s):  
Landau Level ◽  
Optically Pumped ◽  
Optically Pumped Nmr

scholarly journals Oscillations of the cyclotron resonance linewidth with landau level filling factor in GaAs/AlGaAs heterostructures

Physica B+C ◽  
1983 ◽  
Vol 117-118 ◽  
pp. 631-633 ◽  
Author(s):  
Th. Englert ◽  
J.C. Maan ◽  
Ch. Uihlein ◽  
D.C. Tsui ◽  
A.C. Gossard
Keyword(s):  
Landau Level ◽  
Cyclotron Resonance ◽  
Filling Factor ◽  
Resonance Linewidth

FRACTIONAL QUANTUM HALL EFFECT: CONSTRUCTION OF THE HARTREE–FOCK STATE BY USING TRANSLATIONAL COVARIANCE

1994 ◽  
Vol 08 (05) ◽  
pp. 529-579 ◽  
Author(s):  
R. FERRARI
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Landau Level ◽  
Quantum Hall Effect ◽  
Filling Factor ◽  
Quantum Hall ◽  
Fractional Quantum Hall Effect ◽  
Fractional Quantum ◽  
Fractional Quantum Hall ◽  
Hartree Fock

The formalism introduced in a previous paper is used for discussing the Coulomb interaction of many electrons moving in two space-dimensions in the presence of a strong magnetic field. The matrix element of the Coulomb interaction is evaluated in the new basis, whose states are invariant under discrete translations (up to a gauge transformation). This paper is devoted to the case of low filling factor, thus we limit ourselves to the lowest Landau level and to spins all oriented along the magnetic field. For the case of filling factor νf = 1/u we give an Ansatz on the state of many electrons which provides a good approximated solution of the Hartree–Fock equation. For general filling factor νf = u′/u a trial state is given which converges very rapidly to a solution of the self-consistent equation. We generalize the Hartree–Fock equation by considering some correlation: all quantum states are allowed for the u′ electrons with the same translation quantum numbers. Numerical results are given for the mean energy and the energy bands, for some values of the filling factor (νf = 1/2, 1/3, 2/3, 1/4, 3/4, 1/5, 2/5, 3/5, 4/5). Our results agree numerically with the Charge Density Wave approach. The boundary conditions are shown to be very important: only large systems (degeneracy of Landau level over 200) are not affected by the boundaries. Therefore results obtained on small scale systems are somewhat unreliable. The relevance of the results for the Fractional Quantum Hall Effect is briefly discussed.

scholarly journals Quantum Hall–based superconducting interference device

2019 ◽  
Vol 5 (9) ◽  
pp. eaaw8693 ◽  
Author(s):  
Andrew Seredinski ◽  
Anne W. Draelos ◽  
Ethan G. Arnault ◽  
Ming-Tso Wei ◽  
Hengming Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Josephson Junction ◽  
Landau Level ◽  
Carrier Density ◽  
Filling Factor ◽  
Quantum Hall ◽  
Edge States ◽  
Highly Efficient ◽  
Wide Range

We present a study of a graphene-based Josephson junction with dedicated side gates carved from the same sheet of graphene as the junction itself. These side gates are highly efficient and allow us to modulate carrier density along either edge of the junction in a wide range. In particular, in magnetic fields in the 1- to 2-T range, we are able to populate the next Landau level, resulting in Hall plateaus with conductance that differs from the bulk filling factor. When counter-propagating quantum Hall edge states are introduced along either edge, we observe a supercurrent localized along that edge of the junction. Here, we study these supercurrents as a function of magnetic field and carrier density.

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