Mkhitaryan VV, Kagalovsky V, Raikh ME. Microscopic description of a quantum Hall transition without landau levels.
PHYSICAL REVIEW LETTERS 2009;
103:066801. [PMID:
19792593 DOI:
10.1103/physrevlett.103.066801]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Indexed: 05/28/2023]
Abstract
By restricting the motion of a high-mobility 2D electron gas to a network of channels with smooth confinement, we were able to trace, both classically and quantum mechanically, the interplay of backscattering, and of the bending action of a weak magnetic field. Backscattering limits the mobility, while bending initiates quantization of the Hall conductivity. We demonstrate that, in restricted geometry, electron motion reduces to two Chalker-Coddington networks, with opposite directions of propagation along the links, which are weakly coupled by disorder. The interplay of backscattering and bending results in the quantum Hall transition in a nonquantizing magnetic field, which decreases with increasing mobility. This is in accord with the scenario of floating up delocalized states.
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