Quantitative interpretation of thermopower data for composite fermions in a half-filled Landau level

Thermopower data for two 2DEGs with nu = 1/2 at temperatures 0.2 less than or equal to T less than or equal to 1.2 K are explained using the composite fermion (CF) approach. Phonon-drag thermopower dominates at all temperatur es and is treated within the Cantrell-Butcher framework. For T greater than or equal to 1 K the calculated values agree with the data very well. At lo wer T the theory increasingly underestimates the data. This discrepancy is removed completely by modifying the CF-phonon piezoelectric coupling to acc ount for the Chern-Simons gauge field. The only adjustable parameter is the CF mass which is taken to be 1.5m(c).