Strongly coupled edge states in a graphene quantum Hall interferometer

Thomas Werkmeister, James R. Ehrets, Yuval Ronen, Marie E. Wesson, Danial Najafabadi, Zezhu Wei, Kenji Watanabe, Takashi Taniguchi, D. E. Feldman, Bertrand I. Halperin, Amir Yacoby, Philip Kim

Research output: Contribution to journalArticlepeer-review

Abstract

Electronic interferometers using the chiral, one-dimensional (1D) edge channels of the quantum Hall effect (QHE) can demonstrate a wealth of fundamental phenomena. The recent observation of phase jumps in a single edge channel Fabry-Pérot (FP) interferometer revealed anyonic quasiparticle exchange statistics in the fractional QHE. When multiple edge channels are involved, FP interferometers have exhibited anomalous Aharonov-Bohm (AB) interference frequency doubling, suggesting interference of 2e quasiparticles. Here, we use a highly tunable graphene-based QHE FP interferometer to observe the connection between integer QHE interference phase jumps and AB frequency doubling, unveiling the intricate nature of inter edge state coupling in a multichannel QHE interferometer. By tuning the electron density continuously from the QHE filling factor {\nu}<2 to {\nu}>7, we observe periodic interference phase jumps leading to AB frequency doubling. Our observations clearly demonstrate that in our samples the combination of repulsive Coulomb interaction between the spin-split, copropagating edge channels and charge quantization explains the frequency-doubled regime without electron pairing, via a near-perfect anti-correlation between the two edge channels. Our results show that interferometers are sensitive probes of microscopic interactions between edge states, which can cause strong correlations between chiral 1D channels even in the integer QHE regime.
Original languageEnglish
Article number6533
Number of pages10
JournalNature Communications
Volume15
Issue number1
DOIs
StatePublished - 2 Aug 2024

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • General Biochemistry,Genetics and Molecular Biology
  • General Physics and Astronomy

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