Microscopic theory of thermalization in 1D with nonlinear bath coupling

Abstract: Using a non-perturbative classical model, we numerically investigate the dynamics of mobile particles interacting with an infinite chain of harmonic oscillators, an abstraction of ionic conduction through solid-state materials. We show that coupling between the mobile particles and a single mass of the chain is sufficient to induce dissipation of the mobile particles' energy over a wide range of system parameters. When we introduce thermal fluctuations in the position of the chain mass, the mobile particles exhibit thermalization, eventually reaching the same temperature scale as the chain. This model demonstrates how a minimal set of ingredients can exhibit a link between microscopic motion and macroscopic observables, with computationally efficient simulations. Finally, we suggest some experimental platforms that could realize such a model.