Relaxation of charge-density-wave metastable states atT<4.2 K inNbSe3as evidenced in the Shubnikov–de Haas oscillations

Abstract

%e present a study of charge-density-wave metastable states below 4.2 K in thermally quenched NbSe3. These states and their ensuing relaxation are manifest most strongly in the Shubnikov-de Haas (SdH) oscillations. The quenched metastable state remains without any change for time scales ranging from several minutes to several hours before a sharp relaxation is observed. Sharp jumps in the magnetoresistance and the amplitudes of the SdH oscillations are observed when the metastable states relax spontaneously. %'e present evidence that these relaxations are not driven by the magnetic field, H, the current, or a combination of the two. The SdH oscillation frequencies with H parallel to c indicate a 12% decrease in the extremal area of the conduction-electron Fermi surface after relaxation to the equilibrium state. However, the determination of the Hall coefhcient suggests that this change is not simply related to a change in the carrier concentration.

Elasticity and the threshold for stress-induced phase-slip in charge-density waves: predictions of a simple model

“…Neither is it obvious how that state could be distinguished experimentally from the other metastable states, common in pinned CDW, whose relaxation often leads to detectable changes in single-particle transport properties. Of the many observations of such relaxation, those on NbSe3 at temperatures below 4.2 K (t < 0.07) [27] seem the most likely to be of the state in question.…”

Anomalous asymmetry of magnetoresistance in NbSe3 single crystals

“…When magnetic field is perpendicular to the b axis of the crystal, the magnetoresistance of NbSe 3 first rapidly increases with magnetic field, then, at a certain field, its growth becomes much slower. How-ever, the resistance is not saturated and, in high magnetic fields, the nonoscillating component of magnetoresistance linearly varies with magnetic field 16,17,18,19,20 . In weak magnetic fields, a quantum size effect is observed for magnetic field orientations along the conducting layers (in the (bc) plane of the crystal) 21 .…”