Temperature fluctuations in canonical systems: Insights from molecular dynamics simulations

التفاصيل البيبلوغرافية
العنوان: Temperature fluctuations in canonical systems: Insights from molecular dynamics simulations
المؤلفون: Hickman, J., Mishin, Y.
المصدر: Phys. Rev. B 94, 184311 (2016)
سنة النشر: 2016
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Statistical Mechanics
الوصف: Molecular dynamics simulations of a quasi-harmonic solid are conducted to elucidate the meaning of temperature fluctuations in canonical systems and validate a well-known but frequently contested equation predicting the mean square of such fluctuations. The simulations implement two virtual and one physical (natural) thermostat and examine the kinetic, potential and total energy correlation functions in the time and frequency domains. The results clearly demonstrate the existence of quasi-equilibrium states in which the system can be characterized by a well-defined temperature that follows the mentioned fluctuation equation. The emergence of such states is due to the wide separation of timescales between thermal relaxation by phonon scattering and slow energy exchanges with the thermostat. The quasi-equilibrium states exist between these two timescales when the system behaves as virtually isolated and equilibrium.
Comment: Accepted for publication in the Physical Review B
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevB.94.184311
URL الوصول: http://arxiv.org/abs/1609.03646
رقم الأكسشن: edsarx.1609.03646
قاعدة البيانات: arXiv
الوصف
DOI:10.1103/PhysRevB.94.184311