Non-Equilibrium Thermal Transport from Surface–Gas Interaction under Quantum Statistical Constraints

We theoretically investigate non-equilibrium thermal transport phenomena at gas–solid interfaces, where gas molecules interact with a phonon-active wall surface characterized by Bose–Einstein statistics and finite adsorption potential. In such systems, molecules are selectively re-emitted with higher energies in the normal direction, leading to an effectively elevated temperature—an effect we term the "Izumi effect". Furthermore, when geometric constraints induce anisotropic re-emission, orthogonal directions exhibit preferential relaxation to lower-energy components, resulting in effective cooling; we refer to this as angle-selective heat conduction (ASHeC). These coupled effects are analytically described using an energy transfer model, revealing a clear violation of the ergodic hypothesis due to directionally biased state-space sampling induced by surface interactions. Conventional theoretical frameworks fail to predict such heating phenomena, as they often neglect inelastic adsorption–reemission processes and the quantum statistical nature of phonons. This mechanism shares conceptual similarities with the "ghost effect" in rarefied gas dynamics, wherein non-equilibrium boundary conditions can drive macroscopic transport even under isothermal conditions. (see Sone, Molecular Gas Dynamics, Chapter 10, pp. 449–480)