Correlated carrier dynamics in a superconducting van der Waals heterostructure

Abstract

A study of Berezinskii–Kosterlitz–Thouless transitions in clean, layered two-dimensional superconductors promises to provide insight into a host of novel phenomena like re-entrant vortex-dynamics, underlying unconventional metallic phases, and topological superconductivity. In this Letter, we report the study of charge carrier dynamics in a novel two-dimensional superconducting van der Waals heterostructure comprising of monolayer MoS2 and few-layer NbSe2 (∼15 nm). Using low-frequency conductance fluctuation spectroscopy, we show that the superconducting transition in the system is percolative. We present a phenomenological picture of different phases across the transition correlating with the evaluated noise. The analysis of the higher order statistics of fluctuation reveals non-Gaussian components around the transition indicative of long-range correlation in the system.