Tunable heat rectification by applied mechanical stress

We explore an externally tunable way of producing heat rectification, by means of application of an inhomogeneous distribution of a tensile mechanical stress on heat conducting silicon thin films and graphene ribbons. The resulting strain modifies the thermal conductivity of the material, which, in this way, may be partially tuned from the outside. We calculate the rectification coefficient R as function of the applied strain, of the length of the system, and of the external heat flux. The rectification coefficient of a single device results in R ≃ 1.3 for both systems under consideration. Such a value can be enhanced by connecting in series several devices.