Mode-resolved quantum Langevin theory of multiterminal coherent phonon transport
Phys. Rev. B 113, 024202 – Published 14 January, 2026
DOI: https://doi.org/10.1103/p45s-3np3
Abstract
I introduce a mode-resolved quantum Langevin method that tracks coherent phonon heat transport at any temperature from a single eigendecomposition of the dynamical matrix. The result is a closed-form, multiterminal conductance . I derive the expressions and provide an analytical connection to nonequilibrium Green's functions (NEGF), recovering the Landauer–Büttiker limit under weak, diagonal damping. Benchmarks on a harmonic chain reproduce the canonical law. A vacancy-defected carbon nanotube shows quantitative agreement with NEGF transmission spectra. I then apply the method to proteins viewed as multiterminal elastic networks, where surface patches and solvent interfaces serve as contacts. The framework yields the full and a mode-level diagnostic linking conductance, frequency, and localization. The ensuing spectral weights reveal a mobility edge via a temperature crossover . The approach yields fast, interpretable predictions for complex phonon systems from a single eigensolve.