Macroscopic coherence length of charge-density waves in orthorhombic TaS3

Four-probe continuous and pulsed dc current-voltage measurements on orthorhombic Ta${\mathrm{S}}_3$ showed that the distance between potential contacts influences (i) the sharpness of metal-semiconductor transition and (ii) the threshold potential at which, in the low-temperature phase, nonlinearity sets in. The closeness of voltage contacts on the 100-μm scale smears out the phase transition and increases the threshold field, indicating that the phase coherence of charge-density-wave states is destroyed by the perturbation of contacts.