McCarten J

Charge density wave pinning in NbSe3

Abstract We describe a series of experiments which establish that charge density waves (CDWs) in NbSe 3 are weakly pinned. Size dependence of the threshold electric field E T is substantial in undoped crystals of ordinary dimensions, and occurs because typical crystal thicknesses t are comparable to the bulk transverse CDW phase-phase correlation length L x . When t becomes smaller than L x a crossover from 3D to 2D weak pinning behavior occurs.

Phase slip and the origin of broad-band noise in NbSe3

Abstract We have investigated the phase slip process which occurs between regions with different time-averaged charge density wave velocities. Longitudinal phase slip at electrical contacts is temperature activated and requires a minimum voltage V ps o . We evaluate the characteristic parameters and their dependence on the CDW order parameter Δ(T). Transverse phase slip, or velocity shear, occurs as a finite size effect associated with irregular crystal cross sections, and is the dominant source of broad band noise in NbSe 3 .