Temperature effects on edge-state properties in the integer quantum Hall regime

Article

关键词: MAGNETIC-FIELDS;    ELECTROSTATICS;    CHANNELS;    WIRES;   

DOI  :  10.1103/PhysRevB.65.073305

来源: SCIE

【 摘 要 】

The edge and bulk structure of Landau levels (LL's) in a wide channel at the nu=1 quantum Hall regime is calculated for not-too-low temperatures, (h) over bar omega(c)much greater thank(B)Tmuch greater than(h) over barv(g)/2l(0), where v(g) is the group velocity of the edge states and l(o) = root(h) over barc/\e\B is the magnetic length. Edge-states correlations essentially modify the spatial behavior of the lowest spin-up LL, which is occupied, compared to the lowest spin-down LL, which is empty. The influence of many-body interactions on the spatially inhomogeneous spin splitting between the two-lowest LL's is studied within the generalized local-density approximation. Temperature effects on the enhanced spin splitting, the position of the Fermi level within the exchange enhanced gap, and the renormalization of edge-states group velocity by edge-states screening are considered. It is shown that the maximum activation energy G in the bulk of the channel is determined by the gap between the Fermi level and the bottom of the spin-down LL, because the gap between the Fermi level and the spin-up LL is much larger. For the maximum value of G, it is shown that the renormalized group velocity v(g)proportional toT for T --> 0 and, in particular, the condition of not-too-low T can be satisfied for 4.2greater than or similar toTgreater than or similar to0.3 K. In other words, the regime of not-too-low temperatures regime can be achieved even for rather low T.

【 授权许可】

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