Phenomenological theory of heat transport in the fractional quantum Hall effect

Seminar über Theoretische Festkörperphysik

Vortragender:

Amit Aharon

Datum:

18.11.2019 14:00

Ort:

Room 10.01, 10th Floor, Bldg. 30.23, KIT Campus South

Zugehörigkeit:

Weizmann Institute of Science, Rehovot, Israel

Gastgeber:

PD Igor Gornyi

Abstract

The thermal Hall conductance is a universal and topological property which characterizes the fractional quantum Hall (FQH) state. The quantized value of the thermal Hall conductance has recently been measured experimentally in integer quantum Hall (IQH) and FQH regimes, however, the existing setup is not able to detect if the thermal current is counter-propagating or co-propagating with the charge current. Furthermore, although there is experimental evidence for heat transfer between the edge modes and the bulk, the current theories do not take this dissipation effect into consideration. In this talk, I will construct phenomenological rate equations for the heat currents which include equilibration processes between the edge modes [1] and energy dissipation to an external thermal bath. Solving these equations in the limit where the temperature bias is small, we compute the temperature profiles of the edge modes in a FQH state, from which we infer the two-terminal thermal conductance of the state as a function of the coupling to the external bath. I will show that the two-terminal thermal conductance depends on the coupling strength, and can be non-universal when this coupling is very strong. Furthermore, I will propose an experimental setup to examine this theory, which may also allow the determination of the sign of the thermal Hall conductance [2].

Refs:
[1] M. Banerjee, M. Heiblum, A. Rosenblatt, Y. Oreg, D. E. Feldman, A. Stern and V. Umansky, “Observed quantization of anionic heat flow”, Nature, 545, 75 (2016).
[2] Amit Aharon-Steinberg, Yuval Oreg, Ady Stern, “Phenomenological theory of heat transport in the fractional quantum Hall effect”, Phys. Rev. B, 99, 041302 (2019).