Extracting the anyonic exchange phase from co-tunneling through an open quantum dot
Abstract
The elementary excitations of fractional quantum Hall states obey anyonic statistics, described by an exchange phase θ intermediate between the bosonic and fermionic values. We study an interferometer in which three chiral edge segments are pairwise connected by three quantum point contacts, so that, depending on the applied voltages, one of the segments acts as an open quantum dot: its spectrum is continuous, and tunneling through it is resonant without any gate tuning. This setup realizes the co-tunneling mechanism of a recently proposed antidot interferometer in a particularly simple setting. Using a non-equilibrium Keldysh calculation to third order in the tunneling amplitudes, we show that the interference current contains a co-tunneling contribution in which two quasiparticles are exchanged, so that for Laughlin states the exchange phase θ=πν appears as the phase shift between the Aharonov-Bohm oscillations measured in two voltage configurations. We obtain a closed analytic expression for the interference current at finite temperature and finite separation between the quantum point contacts and show that, provided voltage-induced changes of the enclosed area are sufficiently screened, the exchange phase can be extracted from a robust phase-plateau difference. Alternatively, simultaneous measurements of the interference currents at two drains avoid this screening assumption and time-of-flight phases can be quantified analytically, allowing the exchange phase to be extracted by a controlled extrapolation with a few-percent systematic error.
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BibTeX
@misc{puster2026extracting,
title = {{Extracting the anyonic exchange phase from co-tunneling through an open quantum dot}},
author = {Felix Puster and Matthias Thamm and Bernd Rosenow},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.35480},
eprint = {2609.35480},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.35480},
}
RIS
TY - UNPB
TI - Extracting the anyonic exchange phase from co-tunneling through an open quantum dot
AU - Felix Puster
AU - Matthias Thamm
AU - Bernd Rosenow
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.35480
UR - https://arxiv.org/abs/2609.35480
AB - The elementary excitations of fractional quantum Hall states obey anyonic statistics, described by an exchange phase θ intermediate between the bosonic and fermionic values. We study an interferometer in which three chiral edge segments are pairwise connected by three quantum point contacts, so that, depending on the applied voltages, one of the segments acts as an open quantum dot: its spectrum is continuous, and tunneling through it is resonant without any gate tuning. This setup realizes the co-tunneling mechanism of a recently proposed antidot interferometer in a particularly simple setting. Using a non-equilibrium Keldysh calculation to third order in the tunneling amplitudes, we show that the interference current contains a co-tunneling contribution in which two quasiparticles are exchanged, so that for Laughlin states the exchange phase θ=πν appears as the phase shift between the Aharonov-Bohm oscillations measured in two voltage configurations. We obtain a closed analytic expression for the interference current at finite temperature and finite separation between the quantum point contacts and show that, provided voltage-induced changes of the enclosed area are sufficiently screened, the exchange phase can be extracted from a robust phase-plateau difference. Alternatively, simultaneous measurements of the interference currents at two drains avoid this screening assumption and time-of-flight phases can be quantified analytically, allowing the exchange phase to be extracted by a controlled extrapolation with a few-percent systematic error.
ER -