Nonlinear conduction in the spin-density wave phase of (TMTSF)2AsF6

We observed the current-voltage relation in the spin-density wave (SDW) phase of sightly pressurized (TMTSF)2AsF6 above 0.6 K to investigate the SDW dynamics. In the entire temperature range below a transition temperature of ∼ 10 K, the ohmic and non-ohmic regions are clearly distinguished by the well-defined threshold electric field. The SDW dynamics show anomalies at ∼ 3 K and, only below ∼ 3 K, 'transient voltage oscillation', 'narrow band noise' and dielectric voltage response for constant pulse current can be observed. In (TMTSF)2PF6, the sub-phase transitions at ∼ 3 K and ∼ 1 K have been reported. Relations between the SDW dynamics and the sub-phase transitions are discussed