Collective Dynamics and Strong Pinning of Charge-Density-Wave Order in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$

摘要

The dynamics of charge-ordered states is one of the central unresolved issuesin underdoped cuprate high-temperature superconductors. Static short-rangecharge-density-wave (CDW) domains have been detected in almost all cuprates,including La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$, in which CDW order isstabilized by a structural transition. We probe the dynamics across the CDW andstructural transition in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$ by measuringnonequilibrium charge transport, or resistance $R$ as the system responds to achange in temperature and to an applied magnetic field. We find evidence forcollective dynamics of domains in the CDW-ordered phase: although they arestrongly pinned by disorder, the domains are not static, but trapped inlong-lived metastable states. Surprisingly, nonequilibrium effects, such asavalanches in $R$, are revealed only when the transition is approached from thecharge-ordered phase. By unveiling the asymmetry of the transition, this workalso points a way to detecting fluctuating CDWs in other cuprates and variousstrongly-correlated materials.