Dissipative preparation of many-body spin steady states using trapped ultracold atoms

This article presents a dissipative method of creating a spin steady state, or a state whose spin expectation values approaches a fixed value over time, using a trapped gas of ultracold atoms coupled to a background BEC. The ultracold atoms are trapped in a double potential well embedded in a wide harmonic trap, which has a higher energy level than the double wells. The trapped atoms are then excited out of the double well trap into the harmonic trap using Raman lasers. Due to the coupling of the system to the background BEC, the atoms are then able to return to the double potential well by emitting an excitation into the background BEC, which serves as a reservoir of these excitations. By repeatedly coupling and uncoupling the trapped ultracold atoms and the background BEC over fixed intervals of time, the expectation value of the total spin of these atoms will, over time, reach a steady-state value.