THRESHOLD ELECTRIC-FIELD FOR DEPINNING OF THE SPIN-DENSITY-WAVE IN (TMTSF)2ASF6

The threshold electric field (Er) for depinning of the spin density wa ve (SDW) in (TMTSF)2AsF6 has been measured under pressure below 0.4 GP a. Within the pressure range studied E(T) decreases with increasing te mperature up to the transition temperature. The results are compared w ith the theory by Maki and Virosztek. It is likely that, contrary to t he general belief, the SDW in (TMTSF)2AsF6 is commensurate, not incomm ensurate. Below 3 K temperature the dependence of E(T) becomes stronge r and the ratio of the non-ohmic conductivity to the ohmic component d ecreases. Some changes in the SDW phase occur at 3K.