scholarly journals Theory of Shubnikov–de Haas oscillations around the ν=1/2 filling factor of the Landau level: Effect of gauge-field fluctuations

1995 ◽  
Vol 52 (7) ◽  
pp. 4708-4711 ◽  
Author(s):  
A. G. Aronov ◽  
E. Altshuler ◽  
A. D. Mirlin ◽  
P. Wölfle
1995 ◽  
Vol 51 (16) ◽  
pp. 10779-10788 ◽  
Author(s):  
Yong Baek Kim ◽  
Patrick A. Lee ◽  
Xiao-Gang Wen ◽  
P. C. E. Stamp

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

1994 ◽  
Vol 08 (05) ◽  
pp. 529-579 ◽  
Author(s):  
R. FERRARI

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.


2019 ◽  
Vol 5 (9) ◽  
pp. eaaw8693 ◽  
Author(s):  
Andrew Seredinski ◽  
Anne W. Draelos ◽  
Ethan G. Arnault ◽  
Ming-Tso Wei ◽  
Hengming Li ◽  
...  

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.


1992 ◽  
Vol 263 (1-3) ◽  
pp. 591-594 ◽  
Author(s):  
M. Potemski ◽  
Y.H. Zhang ◽  
M. Hausenblas ◽  
J.C. Maan ◽  
G. Martinez ◽  
...  
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