Many-body Green's function approach to lattice thermal transport

Abstract

Recent progress in understanding thermal transport in complex crystals has highlighted the prominent role of heat conduction mediated by interband tunneling processes, which emerge between overlapping phonon bands (i.e. with energy differences smaller than their broadenings). These processes have recently been described in different ways, relying on the Wigner or Green-Kubo formalism, leading to apparently different results which question the definition of the heat-current operator. Here, we implement a full quantum approach based on the Kubo formula, elucidating analogies and differences with the recently introduced Wigner or Green-Kubo formulations, and extending the description of thermal transport to the overdamped regime of atomic vibrations, where the phonon quasiparticle picture breaks down. We rely on first-principles calculations on complex crystals with ultralow conductivity to compare numerically the thermal conductivity obtained within the aforementioned approaches, showing that at least in the quasiparticle regime the differences are negligible for practical applications.

28 pages, 5 figures

References in corpus (3)

• Microscopic Mechanisms of Glass-Like Lattice Thermal Transport in Cubic Cu${}_{12}$Sb${}_4$S${}_{13}$ Tetrahedrites
• First-principles calculations of phonon frequencies, lifetimes and spectral functions from weak to strong anharmonicity: the example of palladium hydrides
• Glass-Like Thermal Conductivity in Nanostructures of a Complex Anisotropic Crystal

Cited by in corpus (5)

• From Green-Kubo to the full Boltzmann kinetic approach to heat transport in crystals and glasses
• Ab initio Green-Kubo simulations of heat transport in solids: Method and implementation
• Wigner Gaussian dynamics: simulating the anharmonic and quantum ionic motion
• Terahertz ionic Kerr effect: Two-phonon contribution to the nonlinear optical response in insulators
• Abnormal Phonon Angular Momentum due to Off-diagonal Elements in Density Matrix induced by Temperature Gradient