Collective Dynamics and Strong Pinning near the Onset of Charge Order in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$

TL;DR

This study investigates the dynamic behavior of charge-ordered states in a cuprate superconductor, revealing metastable states, collective dynamics, and critical phenomena near the charge order transition, with implications for understanding fluctuating order and stripe theories.

Contribution

It provides experimental evidence of fluctuating charge order and critical dynamics in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$, highlighting strong pinning and nonequilibrium effects near the transition.

Findings

Evidence for metastable states and collective behavior.

Critical regime shows strong disorder pinning.

Nonequilibrium effects emerge near the charge order transition.

Abstract

The dynamics of charge-ordered states is one of the key issues in underdoped cuprate high-temperature superconductors, but static short-range charge-order (CO) domains have been detected in almost all cuprates. We probe the dynamics across the CO (and structural) transition in La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$ by measuring nonequilibrium charge transport, or resistance $R$ as the system responds to a change in temperature and to an applied magnetic field. We find evidence for metastable states, collective behavior, and criticality. The collective dynamics in the critical regime indicates strong pinning by disorder. Surprisingly, nonequilibrium effects, such as avalanches in $R$, are revealed only when the critical region is approached from the charge-ordered phase. Our results on La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_{4}$ provide the long-sought evidence for the fluctuating order across the CO transition, and also set important constraints on theories of dynamic stripes.