New Journal of Physics
Thermodynamic cost of a periodically driven quantum system beyond the adiabatic regime
Xiaoyun Wang, Haowei Wang, Dazhi Xu
Abstract
Abstract Finite-time periodic control of an open quantum system is governed by the competition between nonadiabatic driving and reservoir-induced relaxation. We study this competition in a driven two-level system weakly coupled to a single thermal reservoir. Using a nonadiabatic time-dependent quantum master equation, we construct the periodic steady state and separate the dissipated work per cycle into population and nonadiabatic contributions in the instantaneous energy basis. The cycle work is nonmonotonic in the driving frequencies studied and is dominated near its maximum by the nonadiabatic contribution. Nonmonotonicity persists in the examined coupling, temperature, and transverse-amplitude scans. At low frequencies, the work recovers the inverse-period scaling of slow-driving thermodynamics. At higher frequencies, the nonadiabatic work rate ceases to grow in proportion to the driving frequency, and the accumulated work per cycle decreases. We also find that, at finite speed, the ratio of the upward and downward transition coefficients is not determined by the instantaneous energy gap alone and obtain the leading correction to instantaneous detailed balance through a short-memory expansion. These results identify how nonadiabatic transitions and relaxation jointly set the thermodynamic cost of sustaining a periodic quantum process.