Article Determination of topological edge quantum numbers of fractional quantum Hall phases by thermal conductance measurements

Saurabh Kumar Srivastav ; Ravi Kumar ; Christian Spånslätt ; K. Watanabe SAMURAI ORCID (National Institute for Materials Science) ; T. Taniguchi SAMURAI ORCID (National Institute for Materials Science) ; Alexander D. Mirlin ; Yuval Gefen ; Anindya Das

Collection

Citation
Saurabh Kumar Srivastav, Ravi Kumar, Christian Spånslätt, K. Watanabe, T. Taniguchi, Alexander D. Mirlin, Yuval Gefen, Anindya Das. Determination of topological edge quantum numbers of fractional quantum Hall phases by thermal conductance measurements. Nature Communications. 2022, 13 (1), 5185. https://doi.org/10.1038/s41467-022-32956-z
SAMURAI

Description:

(abstract)

To determine the topological quantum numbers of quantum Hall (QH) states hosting counter-propagating (CP) downstream (Nd) and upstream (Nu) edge modes, it is pivotal to study quantized transport both in the presence and absence of edge mode equilibration. While reaching the non-equilibrated regime is challenging for charge transport, we target here the thermal conductance GQ, which is governed by quantum numbers Nd and Nu. Our experimental setup, realized with a hBN encapsulated graphite gated monolayer graphene device, facilitates experimental control over GQ quantization: For temperatures up to 35mK, our measured GQ at ν = 2/3 and 3/5 (with CP modes) match the quantized values of non-equilibrated regime (Nd + Nu)κ0T, where κ0T is a quanta of GQ. With increasing temperature, GQ decreases and even- tually takes the value of equilibrated regime |Nd − Nu|κ0T. By contrast, at ν =1/3 and 2/5 (no CP modes), GQ remains robustly quantized at Ndκ0T independent of the temperature. Our work opens a new route for finding the topological order of non-Abelian QH states and for accurately characterizing reconstructed edges.

Rights:

Keyword: Topological quantum numbers, fractional quantum Hall, thermal Hall conductance

Date published: 2022-09-03

Publisher: Springer Science and Business Media LLC

Journal:

  • Nature Communications (ISSN: 20411723) vol. 13 issue. 1 5185

Funding:

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1038/s41467-022-32956-z

Related item:

Other identifier(s):

Contact agent:

Updated at: 2025-02-27 16:31:13 +0900

Published on MDR: 2025-02-27 16:31:13 +0900

Filename Size
Filename s41467-022-32956-z.pdf (Thumbnail)
application/pdf
Size 1.23 MB Detail