Characterizing phonon dynamics using stochastic sampling

Journal Article · Mon Mar 21 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4943590· OSTI ID:22596916

Kunal, K.

Predicting phonon relaxation time from molecular dynamics (MD) requires a long simulation time to compute the mode energy auto-correlation function. Here, we present an alternative approach to infer the phonon life-time from an approximate form of the energy auto-correlation function. The method requires as an input a set of sampled equilibrium configurations. A stochastic sampling method is used to generate the equilibrium configurations. We consider a truncated Taylor series expansion of the phonon energy auto-correlation function. The different terms in the truncated correlation function are obtained using the stochastic sampling approach. The expansion terms, thus, obtained are in good agreement with the corresponding values obtained using MD. We then use the approximate function to compute the phonon relaxation time. The relaxation time computed using this method is compared with that obtained from the exact correlation function. The two values are in agreement with each other.

• OSTI ID: 22596916
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 11; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
COMPARATIVE EVALUATIONS
CONFIGURATION
CORRELATION FUNCTIONS
CORRELATIONS
EQUILIBRIUM
EXPANSION
MOLECULAR DYNAMICS METHOD
PHONONS
RELAXATION TIME
SAMPLING
SERIES EXPANSION
SIMULATION
STOCHASTIC PROCESSES