Inverse-current quantum electro-oscillations in a charge-density wave insulator

TL;DR

This paper reports the discovery of intrinsic, reproducible quantum electro-oscillations driven by DC current in charge-density-wave insulators, revealing a new form of quantum oscillation related to coherent density-wave states.

Contribution

It introduces a novel type of quantum oscillation in CDW insulators driven by DC current, expanding understanding of quantum phenomena in condensed matter systems.

Findings

Oscillations are periodic in inverse current (1/I).

Oscillations occur in the Fröhlich conductivity region of CDW flow.

Oscillations disappear after a certain index n reaches 1.

Abstract

Quantum magneto-oscillations have long been a vital subject in condensed matter physics, with ubiquitous quantum phenomena and diverse underlying physical mechanisms. Here, we demonstrate the intrinsic and reproducible DC-current-driven quantum electro-oscillations with a periodicity in the inverse of the current (1/I), in quasi-one-dimensional charge-density-wave (CDW) insulators (TaSe$_4$)$_2$I and TaS$_3$ nanowires. Such oscillations manifest in the nearly infinite Fr\"ohlich conductivity region where the undamped CDW flow forms in a finite electric current, and finally disappear after the oscillation index n reaches 1. A systematic investigation on the effect of temperature and magnetic field establishes that the observed electro-oscillations are a coherent quantum phenomenon. We discuss the possibilities of the physical mechanisms, including the formation of sliding-driven inherent Floquet sidebands. Our results introduce a new member in the family of quantum oscillations, and shed light on plausible avenues to explore novel physics and potential applications of coherent density-wave condensates.