1202.4102 (Yafis Barlas et al.)

Thermopower of Quantum Hall States in Corbino Geometry as a Measure of
Quasiparticle Entropy    [PDF]

Yafis Barlas, Kun Yang

Using the Onsager relation between electric and heat transport coefficients,
and considering the very different roles played by the quantum Hall condensate
and quasiparticles in transport, we argue that near the center of a quantum
Hall plateau thermopower in a Corbino geometry measures {\it "entropy per
quasiparticle per quasiparticle charge"}. This relation indicates that
thermopower measurement in a Corbino setup is a more direct measure of
quasiparticle entropy than in a Hall bar. Treating disorder within the
self-consistent Born approximation, we show through an explicit microscopic
calculation that this relation holds on an integer quantum Hall plateau at low
temperatures. Applying this to non-Abelian quantum Hall states, we argue that
Corbino thermopower at sufficiently low temperature becomes
temperature-independent, and measures the quantum dimension of non-Abelian
quasiparticles that determines the topological entropy they carry.

View original: http://arxiv.org/abs/1202.4102