Sliding conduction by the quasi one-dimensional charge-ordered state in Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$

TL;DR

This study investigates nonlinear conduction in Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$, revealing a unique sliding charge-ordered state in the x=0 material that causes microwave resonance, suggesting a quasi-one-dimensional charge density wave.

Contribution

It presents evidence of a sliding charge-ordered state causing nonlinear conduction in a specific cuprate compound, highlighting a unique behavior in the x=0 material.

Findings

Nonlinear conduction observed in Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$ for x=0, 1, 12.

Unique NLC in the ladder direction of x=0 attributed to sliding charge order.

Resonance at microwave frequencies linked to charge-ordered state.

Abstract

Nonlinear conduction (NLC) of the two-leg spin ladder, Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$, was investigated for the $x$=0, 1 and 12 materials . Although insulating materials ($x$=0 and 1) exibited the NLC both in the ladder- and rung directions, the NLC in the ladder direction of the $x$=0-material was found to be very special. We considered this to be due to the sliding motion of the charge ordered state, which was responsible for the resonance at microwave frequencies. We discussed possible candidates for the charge ordered state responsible for the NLC, including Wigner crystal in quasi one dimension (4$k_F$-CDW).