Enhancement of superconductivity in organic-inorganic hybrid topological materials

TL;DR

This paper demonstrates that organic cation intercalation in layered topological materials like MoTe2 and WTe2 significantly enhances their superconducting transition temperature and stability, offering a practical method to engineer topological superconductivity.

Contribution

It introduces a novel organic cation intercalation technique to control interlayer coupling, improving superconductivity and stability in topological layered materials.

Findings

Enhanced Tc to 7.0 K in intercalated MoTe2

Increased Tc to 2.3 K in intercalated WTe2

Method applicable to various layered crystals

Abstract

Inducing or enhancing superconductivity in topological materials is an important route toward topological superconductivity. Reducing the thickness of transition metal dichalcogenides (e.g. WTe2 and MoTe2) has provided an important pathway to engineer superconductivity in topological matters; for instance, emergent superconductivity with Tc=0.82 K was observed in monolayer WTe2 which also hosts intriguing quantum spin Hall effect, although the bulk crystal is nonsuperconducting. However, such monolayer sample is difficult to obtain, unstable in air, and with extremely low Tc, which could pose a grand challenge for practical applications. Here we report an experimentally convenient approach to control the interlayer coupling to achieve tailored topological properties, enhanced superconductivity and good sample stability through organic cation intercalation of the Weyl semimetals MoTe2 and WTe2. The as-formed organic-inorganic hybrid crystals are weak topological insulators with enhanced Tc of 7.0 K for intercalated MoTe2 (0.25 K for pristine crystal) and 2.3 K for intercalated WTe2 (2.8 times compared to monolayer WTe2). Such organic-cationintercalation method can be readily applied to many other layered crystals, providing a new pathway for manipulating their electronic, topological and superconducting properties.