Topological phase transition in MoTe$_2$: A Review

TL;DR

This review discusses the topological phase transition in MoTe$_2$, exploring its structural, electronic, and superconducting properties, and how various stimuli influence these phase transitions and their potential applications.

Contribution

It provides a comprehensive overview of the topological phase transition in MoTe$_2$, linking structural changes to electronic and superconducting properties, and highlights open questions for future research.

Findings

The phase transition involves a change from 1T' to Td structure.

Stimuli like pressure and doping influence the transition temperatures.

Correlations between structural and superconducting phases are identified.

Abstract

Transition metal dichalcogenides (TMDs) are a branch of two-dimensional materials which in addition to having an easy-to-exfoliate layered structure, also host semiconducting, metallic, superconducting, and topological properties in various polymorphs with potential applications. MoTe$_2$ is an example of such a TMD, which shows semiconducting (in 2H phase), metallic (in 1T' phase), topological Weyl semimetallic and superconducting behavior (in Td phase). Consequently, an extensive amount of research has been done on MoTe$_2$, particularly on the topological phase transition between the metallic-type 1T' phase and the topological Td phase. This phase transition has been reviewed and its association with the crystal structure, charge transport, and electronic band structure is elaborately discussed. Also, the effect of various stimuli like reduced dimensionality, pressure, charge doping, and chemical substitution, which affect the structural transition as well as the superconducting transition temperatures is reviewed; thereby, suggesting certain correlations between the apparently unrelated structural and superconducting phase transitions. The review also brings out some open questions which are likely to interest the community to address the physics associated with the phase transition and its potential applications.