Specific Heat of a Fractional Quantum Hall System

Abstract

Using a time-resolved phonon absorption technique, we have measured the specific heat of a two-dimensional electron system in the fractional quantum Hall effect regime. For filling factors $\nu =5/3,4/3,2/3,3/5,4/7,2/5$ and 1/3 the specific heat displays a strong exponential temperature dependence in agreement with excitations across a quasi-particle gap. At filling factor $\nu =1/2$ we were able to measure the specific heat of a composite fermion system for the first time. The observed linear temperature dependence on temperature down to $T=0.14$ K agrees well with early predictions for a Fermi liquid of composite fermions.

4 pages, 4 figures (version is 1. resubmission: Added a paragraph to include the problems which arise by the weak temperature dependence at ν= 1/2, updated affiliation)

Cited by in corpus (2)

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