Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.44: Poster

Montag, 8. März 2004, 16:30–19:00, Poster A

The Mesoscopic Chiral Metal-Insulator Transition in Quantum Hall Wires — •Stefan Kettemann¹, Alexander Struck¹, Bernhard Kramer¹, and Tomi Ohtsuki² — ¹I. Institut f. Theoretische Physik, Univ. Hamburg, Jungiusstr. 9 20355 Hamburg — ²Department of Physics, Sophia Univ. Kioi-Choi 7-1, Chiyoda-Ku, Tokyo 102-8554, Japan

The localization properties of chiral edge states as function of energy in disordered quantum wires subject to a strong magnetic field are shown analytically and numerically to be driven by crossovers from two- to one-dimensional localization of the bulk states [1]. Chiral-metal to insulator transitions associated with these crossovers are predicted. They are characterized by jumps of the localization length of the edge states from an exponentially large to a finite value. As a result, the two-terminal conductance exhibits at zero temperature discontinuous transitions between exactly integer plateau values and zero, reminiscent of first order phase transitions. [1] S. Kettemann, B. Kramer, T. Ohtsuki, cond-mat/0307044