Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.45: Poster

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

Tunneling of quasiholes in the fractional quantum Hall regime — •Moritz Helias and Daniela Pfannkuche — I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstr. 9, 20355 Hamburg, Germany

The elementary low energy excitations in the fractional quantum Hall (FQH) regime are known to be fractionally charged quasiparticles and quasiholes. Basing on the edge state picture, a non-equilibrium transport theory [1] prepared the ground for experiments on tunneling of quasiparticles between the edges of a quantum point contact (QPC) [2].

Recent measurements [3] on a QPC whose edges carry a dilute current of quasiparticles led to surprising results at low temperature: Quasiparticle tunneling appears to be forbidden in this regime, instead Andreev reflexion could explain the experimental results [4].

In our work we treat a QPC in a finite FQH system by exact numerical diagonalization. Quasiholes are injected, their time evolution is investigated and information about possible tunneling processes can be infered.

[1] Kane, Fisher, PRL 72, p.724 (1994)

[2] Saminadayar et al., PRL 79, p.2526 (1997); Griffith et al., PRL 85, p.3918 (2000)

[3] Chung et al., PRB 67, 201104 (2003)

[4] Kane, Fisher, PRB 67, 045307 (2003)