Laser powered dissipative quantum batteries in atom-cavity QED

The interaction of a three-level atom with the electromagnetic field of a quantum cavity in the presence of a laser field presents a rich behavior in the dispersive regime that we exploit to discuss two quantum batteries. In the first setup, we consider a single three-level atom interacting sequentially with many cavities, each in a thermal state. We show that under this process, the atom converges towards an equilibrium state that displays population inversion. In the second setup, a stream of atoms in a thermal state interacts sequentially with a single cavity initially in a thermal state at the same temperature as the atoms. We show that the cavity's energy increases continuously as the stream of atoms continues to cross, and the cavity does not reach an equilibrium state. After many atoms have traveled, the cavity's state becomes active, storing extractable energy that increases in proportion to the work done by the laser. However, the same dynamics may involve only two cavity levels in an interesting limit called the highly selective regime. In that regime, the cavity reaches an equilibrium state similar to the one of the atom in the first scenario. The charging process we propose is robust. We discuss its thermodynamics and evaluate the energy supplied by the laser, the energy stored in the battery, and, thus, the device's efficiency. We also analyze the role of damping.