Dynamics of Quantum Photocells Driven by Periodic or Stochastic Photon Pulses

We investigate the dynamics of a quantum photocell as a quantum heat engine, driven by external photon pulses. The photocell is assumed to be only in thermal contact with a cold reservoir, and the stream of work sources from a work or hot reservoir is represented by repeated photon pulses. The interaction between photon pulses and the photocell is described by the pumping term in a Lindblad master equation. By solving the Lindblad master equation, we study numerically the dynamics of a photocell driven by periodic, random, and Poisson photon pulses. We find that the fluctuations in power output of the photocell change dramatically, depending on the statistics of photon pulses and the parameters of the photocell. At low power output, the level occupation probabilities change somewhat smoothly over a long-period of time, even if the photocell is driven by random photon pulses. We analyze how the fluctuation in photon pulses affects the fluctuation in power output for various photon pulses and the parameters of the photocell.