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.

arXiv comment4 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)

References in corpus (3)

• Phonon Absorption at the Magneto-Roton Minimum in the Fractional Quantum Hall Effect
• A theory of phonon spectroscopy in the fractional quantum Hall regime
• Spin-pairing instabilities at the coincidence of two Landau levels

Cited by in corpus (5)

• Entanglement area law from specific heat capacity
• A thermodynamic approach to measuring entropy in a few-electron nanodevice
• Specific heat and entropy of fractional quantum Hall states in the second Landau level
• Electronic measurements of entropy in meso- and nanoscale systems
• The intrinsic features of the specific heat at half-filled Landau levels of two-dimensional electron systems