Nanoscale electromechanical resonators as probes of the charge density wave transition in NbSe$_2$

TL;DR

This study uses nanoscale electromechanical resonators made from NbSe$_2$ to investigate charge density wave transitions, revealing significant elastic modulus changes and insights into electronic property modulation at the nanoscale.

Contribution

It introduces nanoscale resonators as sensitive probes for CDW physics, demonstrating enhanced elastic response and coupling effects compared to bulk materials.

Findings

Elastic modulus increases by 10% at CDW transition

Resonators detect nanoscale elastic and electronic property changes

Conductance modulation correlates with CDW order parameter

Abstract

We study nanoelectromechanical resonators fabricated from suspended flakes of NbSe$_2$ (thickness$\sim$30-50 nm) to probe charge density wave (CDW) physics at nanoscale. Variation of elastic and electronic properties accompanying the CDW phase transition (around 30 K) are investigated simultaneously using the devices as self-sensing heterodyne mixers. Elastic modulus is observed to change by 10 per cent, an amount significantly larger than what had been reported earlier in the case of bulk crystals. We also study the modulation of conductance by electric field effect, and examine its relation to the order parameter and the CDW energy gap at the Fermi surface.