Millimetre-wave magnetospectroscopy of (TMTSF)2PF6 under pressure

The mm-wave reflection of (TMTSF)2PF6, measured at a pressure of 10kbar in the frequency range 40 to 285 GHz (1.3 to 9.5 cm−1), for B up to 16.5T and T down to 600mK, shows several transitions to FISDW states, coinciding with features in magnetotransport. One new resonance with a heavy-mass of 1.5me (with Q ≈ 6) exists in the metallic state only, at B < 7.3 T, and can be associated with CR on the open orbit. A lighter one at 0.95me (with Q ≈ 25) persisting both in the metallic and in the FISDW states, may be spin-resonance.