Dissipative cooling towards phantom Bethe states in boundary-driven XXZ spin chain

Abstract

A dissipative method that allows to access the family of phantom Bethe states (PBS) of boundary-driven XXZ spin chains is introduced. The method consists in coupling the ends of the open spin chain to suitable dissipative magnetic baths to force the edge spins to satisfy specific boundary conditions necessary for the PBS existence. Cumulative monotonous depopulation of the non-chiral components of the density matrix with growing dissipation amplitude is analogous to the depopulation of high-energy states in response to thermal cooling. Compared to generic states, PBS have strong chirality, non-trivial topology and carry high spin currents.