Heat transport, governed by Fourier's law and characterized by thermal conductivity, is a fundamental material property. Understanding the microscopic factors influencing this conductivity is crucial for applications ranging from energy technologies to electronics and the design of high-performance insulating materials.
The research, conducted within the Interdisciplinary Laboratory of Physics (LIPhy - UGA/CNRS) and the Laboratory of Physics and Modeling of Condensed Matter (LPMMC - UGA/CNRS), proposes a new calculation method based on Path Integral Monte Carlo (PIMC) simulations. This approach calculates nuclear dynamics by exactly accounting for all quantum effects, which are particularly sensitive at low temperatures and in crystals containing light atoms.
Unlike existing methods, this new approach requires no simplifying assumptions or approximations. It allows for the analytical extension of temporal correlation functions into real time to obtain transport coefficients. The researchers validated this method by studying rare gas crystals, Argon and Neon, achieving results consistent with experimental measurements.
The findings, published in Physical Review Letters, indicate that the qualitative change in low-temperature behavior is associated with a characteristic transport time diverging as T→ 0. This robust method, offering a study framework beyond classical molecular dynamics, should lead to a better understanding of heat transport properties, especially in low-temperature regimes where quantum effects become significant.
