Phonon-drag thermopower of composite fermions at filling factor 3/2

Abstract

We present, for the first time, a quantitative interpretation of the measured diagonal thermopower, S xx , for a 2DEG at filling factor ν=3/2. The S xx data span the temperature range 0.2⩽T⩽1.2 K and show that the phonon-drag thermopower, S xx g , is the dominant contribution at all T. S xx g is calculated by using the standard Cantrell–Butcher formalism within the composite fermion picture. The theoretical results for S xx g agree very well with the experimental data when the value 0.87 m e for the composite fermion mass at ν=3/2 is used. We also calculate the ratio S xx g ( ν=3/2)/ S xx g ( ν=1/2) and we find that it is unity for T⩽0.5 K which is in very good agreement with the experiment.