Cavity Heisenberg-spin-chain quantum battery
Fu-Quan Dou, Hang Zhou, Jianan Sun
Abstract
We propose a cavity Heisenberg-spin-chain (CHS) quantum battery (QB) with the long-range interactions and investigate its charging process. The performance of the CHS QB is substantially improved compared to the Heisenberg spin chain (HS) QB. When the number of spins $N\ensuremath{\gg}1$, the quantum advantage $\ensuremath{\alpha}$ of the QB's maximum charging power can be obtained, which approximately satisfies the superlinear scaling relation ${P}_{\mathrm{max}}\ensuremath{\propto}{N}^{\ensuremath{\alpha}}$. The CHS QB can approach $\ensuremath{\alpha}=2$ by optimizing the parameters. We find that the maximum stored energy of the CHS QB has a critical phenomenon. By analyzing the Wigner function, von Neumann entropy, and logarithmic negativity, we demonstrate that entanglement can be a necessary ingredient for QB to store more energy, but not sufficient.