Determining the phonon DOS from specific heat measurements via maximum entropy methods

TL;DR

This paper introduces a maximum entropy and reverse Monte-Carlo approach to derive phonon density of states from heat capacity data, demonstrating its stability, reliability, and applicability to experimental measurements.

Contribution

It presents a novel, cost-effective method for extracting phonon DOS from heat capacity data using maximum entropy and Monte-Carlo techniques.

Findings

Method accurately recovers phonon DOS from simulated data.

Results are stable and reliable even with noisy data.

Applicable to experimental heat capacity measurements of materials.

Abstract

The maximum entropy and reverse Monte-Carlo methods are applied to the computation of the phonon density of states (DOS) from heat capacity data. The approach is introduced and the formalism is described. Simulated data is used to test the method, and its sensitivity to noise. Heat capacity measurements from diamond are used to demonstrate the use of the method with experimental data. Comparison between maximum entropy and reverse Monte-Carlo results shows the form of the entropy used here is correct, and that results are stable and reliable. Major features of the DOS are picked out, and acoustic and optical phonons can be treated with the same approach. The treatment set out in this paper provides a cost-effective and reliable method for studies of the phonon properties of materials.