Controlled synthesis of MoxW1-xTe2 atomic layers with emergent quantum states

TL;DR

This paper presents a controlled chemical vapor deposition method to synthesize MoxW1-xTe2 atomic layers with tunable composition, enabling the study and manipulation of emergent quantum states like superconductivity and Weyl semimetal behavior.

Contribution

The study introduces a novel CVD technique for producing alloyed MoxW1-xTe2 monolayers with precise composition control, facilitating exploration of their quantum properties.

Findings

Successful synthesis of MoxW1-xTe2 with controlled composition.

Observation of superconducting behavior in Mo-rich samples.

Detection of Weyl semimetal states in W-rich samples.

Abstract

Recently, new states of matter like superconducting or topological quantum states were found in transition metal dichalcogenides (TMDs) and manifested themselves in a series of exotic physical behaviors. Such phenomena have been demonstrated to exist in a series of transition metal tellurides including MoTe2, WTe2 and alloyed MoxW1-xTe2. However, the behaviors in the alloy system have been rarely addressed due to their difficulty in obtaining atomic layers with controlled composition, albeit the alloy offers a great platform to tune the quantum states. Here, we report a facile CVD method to synthesize the MoxW1-xTe2 with controllable thickness and chemical composition ratios. The atomic structure of monolayer MoxW1-xTe2 alloy was experimentally confirmed by scanning transmission electron microscopy (STEM). Importantly, two different transport behaviors including superconducting and Weyl semimetal (WSM) states were observed in Mo-rich Mo0.8W0.2Te2 and W-rich Mo0.2W0.8Te2 samples respectively. Our results show that the electrical properties of MoxW1-xTe2 can be tuned by controlling the chemical composition, demonstrating our controllable CVD growth method is an efficient strategy to manipulate the physical properties of TMDCs. Meanwhile, it provides a perspective on further comprehension and shed light on the design of device with topological multicomponent TMDCs materials.