Finite-time two-spin quantum Otto engines: Shortcuts to adiabaticity vs. irreversibility

We propose a quantum Otto cycle in two spin-1/2 anisotropic XY model transverse external magnetic field. first characterize the parameter regime that working medium operates as an engine adiabatic regime. Then, we consider finite-time behavior of with and without utilizing shortcut to adiabaticity (STA) technique. STA schemes guarantee dynamics system follows path, at expense introducing control. compare performance nonadiabatic engines for fixed efficiency but different parameters medium. observe that, certain regimes, irreversibility, measured by lags, due driving is so low performs quite close engine, leaving only marginally better than one. This suggests designing Hamiltonian one may spare difficulty dealing control protocol.