Magnetothermopower of (TMTSF)2ClO4and a new high-field phase

Abstract
We report the temperature and magnetic-field dependence of the thermopower of (TMTSF)2 ClO4 through the entire range of magnetic-field-induced spin-density-wave (FISDW) transitions. The activated behavior of the thermopower in the extremely stable FISDW state that resembles the 1/3 fractional quantized Hall effect provides strong evidence for a collective ground state. At high magnetic field above 25 T, we find a new phase with a true energy gap at the Fermi level.