The sliding phase transition in ferroelectric van der Waals bilayers

TL;DR

This paper investigates the thermodynamics of sliding in ferroelectric van der Waals bilayers using continuum elasticity theory, explaining the stability of ferroelectricity and comparing theoretical predictions with experimental data.

Contribution

It introduces a continuum elasticity model for sliding thermodynamics in ferroelectric bilayers and links mechanical properties to ferroelectric stability.

Findings

Large in-plane stiffness explains ferroelectric robustness.

Computed critical temperatures align with experimental observations.

Electric susceptibility and heat capacity are quantitatively analyzed.

Abstract

We address the sliding thermodynamics of van der Waals-bonded bilayers by the continuum elasticity theory. We attribute the robustness of the ferroelectricity recently observed in h-BN and WTe2 bilayers to large monolayer in-plane stiffness. We compute the electric susceptibility and specific heat in the mean-field self-consistent phonon approximation. We compare critical temperatures and electric switching fields with the observations.