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  • Letter
  • Open Access

Ballistic-to-diffusive transition in engineered counterpropagating quantum Hall channels

Aifei Zhang1, Kenji Watanabe2, Takashi Taniguchi3, Patrice Roche1, Carles Altimiras1, François D. Parmentier1,4, and Olivier Maillet1,*

  • *Contact author: olivier.maillet@cea.fr
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Phys. Rev. Research 7, L042037 – Published 19 November, 2025

DOI: https://doi.org/10.1103/3d25-wpth

Abstract

Exotic quantum Hall systems hosting counterpropagating edge states can show seemingly nonuniversal 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 counterpropagating 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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References (34)

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Phys. Rev. Research 7, L042037– Published 19 November, 2025
  • Received 28 May 2025
  • Revised 23 August 2025
  • Accepted 14 October 2025
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