Asymmetry in Forward/Backward Transition Times in Multi-Particle System with Interactions

Transition time is a fundamentally important property of various non-equilibrium processes, including biological transport and diffusion through channels that reflect the underlying microscopic dynamics. For single particles moving in arbitrary free-energy landscapes, it is known that the forward and backward transition times are the same due to the microscopic reversibility. To understand how and in which condition the symmetry breaks down, here we investigate a non-equilibrium one-dimensional multi-particle system on the lattice with periodic boundary conditions where the particles interact only via hard-core exclusions. We found the asymmetry in forward/backward transition times for time-averaged situations when the transition events are analyzed from long-time trajectories. We developed a fully analytical theoretical analysis that can describe the observed results. The microscopic origin of these surprising observations is discussed.