Strongly correlated bistable sublattice and temperature hysteresis of elastic and thermal crystal properties

TL;DR

This paper explores how cooperative atomic behavior in crystal lattices with a basis can lead to bistable sublattices, causing hysteresis in elastic and thermal properties, aligning with experimental observations in superconducting cuprates.

Contribution

It introduces a model explaining hysteresis in crystal properties via bistable sublattices formed by atoms in double-well potentials, providing qualitative agreement with experimental data.

Findings

Bistable sublattices cause hysteresis in elastic and thermal properties.

The model explains temperature-dependent ultrasonic wave behavior.

Qualitative agreement with experimental data in cuprates.

Abstract

It is shown that in crystal lattices with a basis the cooperative behavior of a certain type of atoms performing optical long-wavelength vibrations in a double-well potential of the field of the matrix lattice may lead to the formation of a bistable sublattice. As a result of the interaction of the metastable states of such a sublattice with the vibrational states of the matrix lattice, the elastic and thermal properties of the crystal acquire anomalous, hysteresis-like, temperature curves. The concepts developed in the paper make it possible to obtain a qualitative interpretation, which agrees with the experimental data, of the hysteresis-like temperature dependence of the speed and absorption of ultrasonic waves, the specific heat, and the thermal conductivity in superconducting yttrium and bismuth cuprates.