Non-reciprocity drives a Brownian dimer out of equilibrium

We consider the minimal model of a two dimensional Brownian dimer consisting of two overdamped monomers, trapped in an isotropic harmonic potential and mutually coupled by a non-reciprocal harmonic spring that violates Newton's action-reaction principle. We have shown that the non-reciprocal interaction alone can drive the system far from equilibrium, in the absence of any external time dependent drive and being in contact with a single thermal bath. The exact steady state probability distribution and current are explicitly calculated for the zero-rest-length limit of the spring, which eventually maps our model to another non-equilibrium phenomenon, called Brownian gyration. For a spring with finite rest length, these quantities are calculated numerically.