Emergence and control of heat current from strict zero thermal bias

It is an ever-growing challenge to develop nanodevices for controlling energy transport. An open question is whether we can create and control heat current at strict zero thermal bias, and if yes, how to do it. In this paper, we demonstrate that a nonlinear asymmetric system, when pushed out of equilibrium, can produce heat current in the absence of a thermal bias. The emergence and control of heat current over a broad range of parameters are studied. Our results reveal the following three necessary conditions: nonequilibrium source, symmetry breaking, and nonlinearity. We also demonstrate that when heat baths are correlated, symmetry breaking is sufficient to generate heat current.