Thermopower in the quantum Hall regime

Abstract

We consider the effect of disorder on the themopower in quantum Hall systems. For a sample in the Corbino geometry, where dissipative currents are not carried by edge states, we find that thermopower behaves at high temperatures like a system with a gap and has a maximum which increases as the temperature is reduced. At lower temperatures this maximum reduces as a function of temperature as a result of tunneling across saddle points in the background potential. Our model assumes that the mean saddle point height varies linearly with the deviation in filling factor from the quantized value. We test this hypothesis against observations for the dissipative electrical conductance as a function of temperature and field and find good agreement with experiment around the minimum.

5 pages, 4 figures

References in corpus (5)

• Fractional quantum Hall effect at $\nu =5/2$: Ground states, non-Abelian quasiholes, and edge modes in a microscopic model
• Thermopower as a Possible Probe of Non-Abelian Quasiparticle Statistics in Fractional Quantum Hall Liquids
• Thermoelectric response of fractional quantized Hall and re-entrant insulating states in the N=1 Landau level
• Thermopower of Quantum Hall States in Corbino Geometry as a Measure of Quasiparticle Entropy
• Model for Dissipative Conductance in Fractional Quantum Hall States

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• Fractional Quantum Hall States in a Ge Quantum Well
• Second Landau Level Fractional Quantum Hall Effects in the Corbino Geometry
• Quantum Hall interferometry in triangular domains of marginally twisted bilayer graphene
• Thermoelectric cooling properties of a quantum Hall Corbino device
• Thermoelectric properties of the Corbino disk in graphene