Thermoelectric power in between two plateaus in quantum Hall effect

TL;DR

This paper investigates the thermoelectric power between two quantum Hall plateaus, analyzing its temperature dependence and introducing the concept of line width and activation energy to understand the response at these energies.

Contribution

It introduces a method to define thermoelectric power at plateau centers using Hall conductivity and explores its temperature dependence in the quantum Hall regime.

Findings

Thermoelectric power varies as T^2 at low temperatures.

At elevated temperatures, it follows an exponential decay with activation energy.

The response is characterized at energies corresponding to two plateaus.

Abstract

We have considered the response at two energies corresponding to two plateaus in the quantum Hall effect. Since the thermoelectric power involves the derivative of conductivity with respect to energy, we introduce the concept of a line width and hence an activation energy. We then use the Hall conductivity to define the thermoelectric power at the centre of two plateaus, which is found to vary monotonically as T^2 at low temperatures with fixed magnetic field. At elivated temperatures, the thermoelectric power varies as T(exp-\Delta/k_BT).