1D van der Waals Material Tellurium: Raman Spectroscopy under Strain and Magneto-transport

TL;DR

This study experimentally investigates the anisotropic properties of 1D van der Waals tellurium using Raman spectroscopy under strain and magneto-transport measurements, revealing its unique 1D transport characteristics and structural responses.

Contribution

It provides the first experimental evidence of 1D van der Waals tellurium's anisotropic transport and structural properties, highlighting its distinct behavior from other 1D nanowires and 2D materials.

Findings

Pronounced strain response along c-axis due to intra-chain bonds

Distinct magneto-resistance behaviors for different magnetic field directions

Evidence of 1D transport characteristics from phase coherence length analysis

Abstract

Experimental demonstrations of 1D van der Waals material tellurium have been presented by Raman spectroscopy under strain and magneto-transport. Raman spectroscopy measurements have been performed under strains along different principle axes. Pronounced strain response along c-axis is observed due to the strong intra-chain covalent bonds, while no strain response is obtained along a-axis due to the weak inter-chain van der Waals interaction. Magneto-transport results further verify its anisotropic property, resulting in dramatically distinct magneto-resistance behaviors in terms of three different magnetic field directions. Specifically, phase coherence length extracted from weak antilocalization effect, L$_{\Phi}$ ~ T$^{-0.5}$, claims its 2D transport characteristics when an applied magnetic field is perpendicular to the thin film. In contrast, L$_{\Phi}$ ~ T$^{-0.33}$ is obtained from universal conductance fluctuations once the magnetic field is along c-axis of Te, indicating its nature of 1D transport along the helical atomic chains. Our studies, which are obtained on high quality single crystal tellurium thin film, appear to serve as strong evidences of its 1D van der Waals structure from experimental perspectives. It is the aim of this paper to address this special concept that differs from the previous well-studied 1D nanowires or 2D van der Waals materials.