Clean 2D superconductivity in a bulk van der Waals superlattice

TL;DR

This paper reports the creation of a high-quality, clean-limit 2D superconductor using a bulk superlattice of 2H-NbS2, enabling exploration of exotic superconductivity and related quantum phases in a more controlled, low-dimensional environment.

Contribution

The study introduces a novel bulk superlattice structure that enhances two-dimensionality and material quality of TMD superconductors, facilitating research into fragile pairing symmetries and exotic quantum states.

Findings

Realized clean-limit 2D superconductivity in a bulk superlattice.

Enhanced two-dimensionality and electronic quality of the superlattice.

Potential to extend the structure to other TMD-based quantum materials.

Abstract

Advances in low-dimensional superconductivity are often realized through improvements in material quality. Apart from a small group of organic materials, there is a near absence of clean-limit two-dimensional (2D) superconductors, which presents an impediment to the pursuit of numerous long-standing predictions for exotic superconductivity with fragile pairing symmetries. Here, we report the development of a bulk superlattice consisting of the transition metal dichalcogenide (TMD) superconductor 2$H$-niobium disulfide (2$H$-NbS$_2$) and a commensurate block layer that yields dramatically enhanced two-dimensionality, high electronic quality, and clean-limit inorganic 2D superconductivity. The structure of this material may naturally be extended to generate a distinct family of 2D superconductors, topological insulators, and excitonic systems based on TMDs with improved material properties.