Condensed Matter Physics Seminar

Optimal control of quantum evolution provides a shortcut to adiabaticity, resulting in fast and precise preparation of states with various desired properties. We propose a general scheme for nonadiabatic cooling of quantum systems, and apply it to a system of two one-dimensional quasicondensates coupled with a time-varying tunneling amplitude. We show that for this system, the optimal protocol for maximizing any figure of merit in a given time is bang-bang, i.e., the coupling alternates between only two values through a sequence of sudden quenches. Minimizing the energy of one of the quasicondensates with such nonadiabatic protocols, and then decoupling it at the end of the process, leads to effective cooling beyond the current state of the art.