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

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) insulator (TaSe₄)₂I and TaS₃ 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 member in the family of quantum oscillations and shed light on plausible avenues to explore the physics and potential applications of coherent density-wave condensates.