Odd transport in a two-temperature Brownian dimer

Abstract

We investigate a two-temperature Brownian dimer with odd mobility, characterized by antisymmetric transport coefficients, as a controlled paradigm for odd nonequilibrium dynamics. The system is made of two harmonically confined particles coupled by an elastic spring and connected to reservoirs at different temperatures. Odd mobility converts conservative forces into transverse motion, linking heat exchange to circulating probability currents without requiring external torques, spatial anisotropy, or nonconservative driving. Our exact solution shows that odd mobility creates handed correlations between the two particles while leaving the individual particle distributions isotropic. These correlations arise only when temperature imbalance, elastic coupling, and odd mobility act together, and their handedness reverses when the odd response is reversed. The steady probability current contains two distinct parts: the ordinary irreversible current of a two-temperature dimer and an additional handed contribution generated by odd mobility. When projected onto the motion of each particle, this handed contribution becomes a pair of counter-rotating circulating currents inside the traps. Based on the currents we compute the heat transfer and entropy production analytically. We show that odd mobility enhances thermal conductance between the reservoirs, while the net heat current and total dissipation remain unchanged under reversal of the odd handedness.