Thermoelectric properties of Coulomb-blockaded fractional quantum Hall islands

TL;DR

This paper demonstrates how to compute thermoelectric properties of Coulomb-blockaded fractional quantum Hall islands at non-zero temperature using conformal field theory, revealing insights into edge mode velocities and universality classes.

Contribution

It introduces a method to calculate thermoelectric characteristics of fractional quantum Hall islands using conformal field theory partition functions, enabling experimental distinction of universality classes.

Findings

Thermopower oscillations are sensitive to neutral multiplicities.

Proposed measurement of edge mode velocity ratio from power-factor data.

Method allows spectroscopic analysis of quantum Hall edge states.

Abstract

We show that it is possible and rather efficient to compute at non-zero temperature the thermoelectric characteristics of Coulomb blockaded fractional quantum Hall islands, formed by two quantum point contacts inside of a Fabry-Perot interferometer, using the conformal field theory partition functions for the chiral edge excitations. The oscillations of the thermopower with the variation of the gate voltage as well as the corresponding figure-of-merit and power factors, provide finer spectroscopic tools which are sensitive to the neutral multiplicities in the partition functions and could be used to distinguish experimentally between different universality classes. We also propose a procedure for measuring the ratio r=v_n/v_c of the Fermi velocities of the neutral and charged edge modes for filling factor \nu=5/2 from the power-factor data in the low-temperature limit.