SnAs-based layered superconductor NaSn2As2

TL;DR

This paper reports the discovery of superconductivity in the layered tin arsenide NaSn2As2, highlighting its potential as a new platform for studying low-dimensional superconductors with unique electronic properties.

Contribution

It introduces NaSn2As2 as a new layered superconductor with a specific crystal structure, expanding the family of low-dimensional superconducting materials.

Findings

Superconductivity confirmed with Tc of 1.3 K

Layered structure with van-der-Waals bound bilayers

Proposes SnAs layers as a universal structure in layered superconductors

Abstract

Superconductivity with exotic properties has often been discovered in materials with a layered (two-dimensional) crystal structure. The low dimensionality affects the electronic structure of materials, which could realize a high transition temperature (Tc) and/or unconventional pairing mechanisms. Here, we report the superconductivity in a layered tin arsenide NaSn2As2. The crystal structure consists of (Sn2As2)2- bilayers, which is bound by van-der-Waals forces, separated by Na+ ions. Measurements of electrical resistivity and specific heat confirm the bulk nature of superconductivity of NaSn2As2 with Tc of 1.3 K. Our results propose that the SnAs layers will be a basic structure providing another universality class of a layered superconducting family, and it provides a new platform for the physics and chemistry of low-dimensional superconductors with lone pair electrons.