Magnetic and electronic phase transitions probed by nanomechanical resonance

TL;DR

This paper demonstrates that nanomechanical resonators can effectively probe magnetic and electronic phase transitions in 2D materials by detecting anomalies in resonance frequency and quality factor related to phase changes.

Contribution

It introduces a novel method using nanomechanical resonance to study phase transitions in 2D materials, including challenging antiferromagnetic phases.

Findings

Resonance frequency and quality factor anomalies correlate with phase transition temperatures.

Mechanical motion couples to magnetic and electronic order parameters.

Method applicable to various materials, including insulating and antiferromagnetic ones.

Abstract

Two-dimensional (2D) materials enable new types of magnetic and electronic phases mediated by their reduced dimensionality like magic-angle induced phase transitions, 2D Ising antiferromagnets and ferromagnetism in 2D atomic layers and heterostructures. However, only a few methods are available to study these phase transitions, which for example is particularly challenging for antiferromagnetic materials. Here, we demonstrate that these phases can be probed by the mechanical motion: the temperature dependent resonance frequency and quality factor of multilayer 2D material membranes show clear anomalies near the phase transition temperature, which are correlated to anomalies in the specific heat of the materials. The observed coupling of mechanical degrees of freedom to magnetic and electronic order is attributed to thermodynamic relations that are not restricted to van der Waals materials. Nanomechanical resonators, therefore, offer the potential to characterize phase transitions in a wide variety of materials, including those that are antiferromagnetic, insulating or so thin that conventional bulk characterization methods become unsuitable.