Atomic-superfluid heat engines controlled by twisted light

Abstract: We theoretically propose a quantum heat engine using a setup consisting of a ring-trapped Bose-Einstein condensate placed in a Fabry--P\'erot cavity where the optical fields carry orbital angular momentum. We first show that the cavity-enhanced light-atom coupling leads to the emergence of polaritonic modes, whose character can be reversibly switched between photonlike and phononlike by detuning sweeps allowing work extraction governed by distinct reservoirs. We investigate the dependence of the engine efficiency on the orbital angular momentum. Beyond ideality, we discuss finite-time scenarios based on shortcuts to adiabaticity such that the efficiency retains its ideal-operation value, despite finite-time challenges. Finally, for lower values of the orbital angular momentum, we describe an alternate scheme for operating quantum heat engines based on the adiabatic elimination of a mechanical mode. Our analysis identifies orbital angular momentum as an experimentally-accessible control knob that can reconfigure the performance of such quantum heat engines as desired.