Abstract
A steady current between baths is a manifestation of the prethermalization phenomenon, a quasiequilibriumdynamic process with weak breaking of conserved quantities. We consider two finite nonintegrable many-bodybaths, each following the eigenstate thermalization hypothesis and each prepared in a random product state withfixed and different energy constraints, i.e., within the mean energy ensemble. Such an initialization, not beingconstrained to superpositions or mixtures of many-body eigenstates, opens the door to experimental realizationand also significantly simplifies numerical simulations. We show that such a dynamic process is typical as thecurrent variance decreases exponentially with respect to the size of baths. We also demonstrate that the emergingcurrent is prethermalized in a strong sense, analogous to strong thermalization, meaning that the current valuesstay close to the microcanonical one most of the time