Crystal size effect on the spin-density wave dynamics in (TMTSF)2AsF6

Using thin crystals of (TMTSF)2AsF6 the threshold electric field (ET) for the spin density wave (SDW) depinning was determined. At 4.2K, ET increases with decreasing cross-sectional area and it is as large as 100 mV/cm in the thinnest sample studied. It increases with temperature very weakly up to the transition temperature, in contrast with thicker ones in which ET decreases strongly with temperature.