Finite-temperature fractional quantum Hall effect

We investigate the fractional quantum Hall effect at finite temperature using a fermion Chern-Simons field-theoretical approach. In the absence of impurity scattering, the essential aspects of the fractional quantum Hall effect, such as the quantization of Hall conductance, as well as quasiparticle charge and statistics are not renormalized by thermal fluctuations. On the other hand, we find that the low-energy excitation spectrum at finite T may undergo some qualitative changes as the temperature is raised. Interesting new features include a splitting of the low-energy collective modes and a redshift of the magnetoroton minimum at finite T. Possible experimental consequences are discussed