Optomechanically-induced chiral transport of phonons in one dimension
This paper (https://arxiv.org/abs/1701.02699) is an expansion and extention to our previous theoretical work (https://arxiv.org/abs/1612.09240). In contrast to previous work, here we directly consider the many-mode behavior of the system and use a simple diagrammatic perturbation theory to connect experimentally measurable quantities in the optics to the phonon diffusion. The main result seems rather simple and easy to understand, which is summarized by the diagram shown above (also in Fig. 3 of the paper), but actually it takes the authors a long time to finally arrive at this result. The chiral transport of phonons is due to the directional optomechanical coupling to the optical fields, which eventually modifies the phonon propagator in an asymmetric manner for forward propagating and backward propagating directions. The analytical results for phonon diffusion is also confirmed by the numerical calculation, which is shown in Fig. 4.