Measuring Topological Entanglement Entropy Using Maxwell Relations

Sarath Sankar, Eran Sela, Cheolhee Han

Research output: Contribution to journalArticlepeer-review


Topological entanglement entropy (TEE) is a key diagnostic of topological order, allowing one to detect the presence of Abelian or non-Abelian anyons. However, there are currently no experimentally feasible protocols to measure TEE in condensed matter systems. Here, we propose a scheme to measure the TEE of chiral topological phases, carrying protected edge states, based on a nontrivial connection with the thermodynamic entropy change occurring in a quantum point contact (QPC) as it pinches off the topological liquid into two. We show how this entropy change can be extracted using Maxwell relations from charge detection of a nearby quantum dot. We demonstrate this explicitly for the Abelian Laughlin states, using an exact solution of the sine-Gordon model describing the universal crossover in the QPC. Our approach might open a new thermodynamic detection scheme of topological states also with non-Abelian statistics.

Original languageEnglish
Article number016601
JournalPhysical Review Letters
Issue number1
StatePublished - 7 Jul 2023

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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