Catalogue of phonon modes in several cuprate high-temperature superconductors from density functional theory

TL;DR

This study provides a comprehensive reference of phonon modes in key cuprate high-temperature superconductors using density functional theory, aiding future research into their properties.

Contribution

It offers the first complete computational catalog of phonon frequencies and atomic displacements for several cuprate superconductors, aligning with symmetry expectations.

Findings

Phonon modes match symmetry predictions.

Identified instabilities related to structural phase transitions.

Provides a reference for future experimental and theoretical studies.

Abstract

Cuprates are promising candidates for study in developing higher temperature superconductors. A thorough understanding of a material's phonon modes enables further investigation of its emergent properties, however, no complete reference of the phonon modes exists. Here, using density functional theory, we evaluate the phonon frequencies and atomic displacements for $\text{La}_2\text{CuO}_4$, $\text{Bi}_2\text{Sr}_2\text{CuO}_6$, and $\text{Bi}_2\text{Sr}_2\text{CaCu}_2\text{O}_8$ in their tetragonal structures. The phonon modes for all materials agree with those expected from space group symmetry and display instabilities corresponding to known low-temperature structural phase transitions.