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arXiv · 2505.05386

Ballistic-to-diffusive transition in engineered counter-propagating quantum Hall channels

Aifei Zhang·Kenji Watanabe·Takashi Taniguchi·Patrice Roche·Carles Altimiras·François D. Parmentier·Olivier Maillet
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Abstract

Exotic quantum Hall systems hosting counter-propagating edge states can show seemingly non-universal transport regimes, usually depending on the size of the sample. We experimentally probe transport in a quantum Hall sample engineered to host a tunable number of counter-propagating edge states. The latter are coupled by Landauer reservoirs, which force charge equilibration over a tunable effective length. We show that charge transport is determined by the balance of up- and downstream channels, with a ballistic regime emerging for unequal numbers of channels. For equal numbers, we observe a transition to a critical diffusive regime, characterized by a diverging equilibration length. Our approach allows simulating the equilibration of hole-conjugate states and other exotic quantum Hall effects with fully controlled parameters using well-understood quantum Hall states.

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Aifei Zhang, Kenji Watanabe, Takashi Taniguchi, Patrice Roche, Carles Altimiras, François D. Parmentier, Olivier Maillet. 2025-05-08. Ballistic-to-diffusive transition in engineered counter-propagating quantum Hall channels. https://doi.org/10.1103/3d25-wpth

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