Evidence for Correlated Dynamics near the Berezinskii-Kosterlitz-Thouless-like Transition in Highly Underdoped La${}_{2-x}$Sr${}_x$CuO${}_4$

Abstract

A low-frequency resistance noise study in highly underdoped thick films of La${}_{2-x}$Sr${}_x$CuO${}_4$ ($x=0.07$ and 0.08) reveals slow, correlated dynamics and breaking of ergodicity near the superconducting transition of the Berezinskii-Kosterlitz-Thouless type. The observed correlated behavior is strongly suppressed by disorder.

6 pages, 5 figures