Tunable superconductivity coexisting with the anomalous Hall effect in 1T'-WS2

TL;DR

This study demonstrates that applying hydrostatic pressure to 1T'-WS2 induces a sequence of electronic phase transitions, including suppression and reemergence of superconductivity, alongside the emergence of an anomalous Hall effect, revealing a highly tunable quantum material.

Contribution

We show that pressure tuning in 1T'-WS2 induces multiple electronic phases, including topological, superconducting, and anomalous Hall states, with distinct pairing symmetries and band structures.

Findings

Pressure induces a dual phase transition in 1T'-WS2.

Superconductivity reemerges at high pressure with increased anisotropy.

First-principles calculations reveal a transition to a strong topological phase.

Abstract

Transition metal dichalcogenides are a family of quasi-two-dimensional materials that display a high technological potential due to their wide range of electronic ground states, e.g., from superconducting to semiconducting, depending on the chemical composition, crystal structure, or electrostatic doping. Here, we unveil that by tuning a single parameter, the hydrostatic pressure P, a cascade of electronic phase transitions can be induced in the few-layer transition metal dichalcogenide 1T'-WS2, including superconducting, topological, and anomalous Hall effect phases. Specifically, as P increases, we observe a dual phase transition: the suppression of superconductivity with the concomitant emergence of an anomalous Hall effect at P=1.15 GPa. Remarkably, upon further increasing the pressure above 1.6 GPa, we uncover a reentrant superconducting state that emerges out of a state still exhibiting an anomalous Hall effect. This superconducting state shows a marked increase in superconducting anisotropy with respect to the phase observed at ambient pressure, suggesting a different superconducting state with a distinct pairing symmetry. Via first-principles calculations, we demonstrate that the system concomitantly transitions into a strong topological phase with markedly different band orbital characters and Fermi surfaces contributing to the superconductivity. These findings position 1T'-WS2 as a unique, tunable superconductor, wherein superconductivity, anomalous transport, and band features can be tuned through the application of moderate pressures.