High-efficiency and noise-immune quantum battery

Abstract

Nowadays, quantum batteries (QBs) have been designed to outperform their classical counterparts by leveraging quantum advantages. For instance, the charging power greatly benefits from the entanglement generation of a collective charging scheme (e.g., the Dicke QB), especially in the ultrastrong coupling (USC) regime or even larger. However, apart from the fragility of the QB under intrinsic decoherence effects, another critical drawback emerges inevitably. Specifically, the non-negligible counter-rotating (CR) term in the USC regime would induce coherence in the energy basis of QB, thus remarkably degrading the charging efficiency. To tackle these challenges, we propose a high-efficiency and noise-immune QB boosted by dynamical modulation. It is demonstrated that the time-varying modulation can effectively reduce the CR coupling, resulting in a notable improvement in charging efficiency. Particularly, for a judicious choice of modulation parameters that entirely eliminate the CR interaction, the Dicke QB can be charged optimally, resembling the behavior of the Tavis-Cummings QB. In the subsequent storage process, beyond the natural robustness to pure dephasing noise, our scenario is also highly resilient to the dissipation noise and thus can achieve perfect energy storage by effective bath engineering. While feasible with current experimental platforms, our proposal offers a solid foundation for the implementation of a powerful QB and may drastically promote the development of energy storage and delivery techniques in the future.

Figures (6)

• Figure 1: (a) The schematic diagram of the QB in the charging and storage process. (b) The efficiency (mean ergotropy) of the QB versus time. The red solid line (black dotted line) represents the efficiency of the Dicke QB under noise (TC QB without noise). The charging time $\tau_{\mathrm{c}}$ is chosen as the one when efficiency reaches its first maximum. The initial state of the system is $\left|\varphi(0)\right\rangle =\left|N/2,-N/2\right\rangle \left|N\right\rangle _{c}$. Here $g/\omega_{0}=1$, $N=8$, and $\Gamma_{0}/\omega_{0}=0.1$.
• Figure 2: (a) The schematic diagram of the influence of the DM on the CR coupling in the charging process. In the large-frequency limit, the CR Rabi frequency is reduced from $g$ to $gJ_{0}(2\xi)$. (b) The QB-charger transition process. The red solid (green dashed) arrows stand for the transitions originating from the rotating (CR) interaction. (c) The schematic diagram of the influence of the DM on the QB-environment interaction in the storage process. In the large-frequency limit, the effective dissipation rate of the QB is shrunk from $\Gamma_{0}\equiv2\pi D(\omega_{0})$ to $J_{0}^{2}(\xi)\Gamma_{0}$.
• Figure 3: The dynamics of the efficiency (a) and coherence (b) of the QB versus charging time. The gray (orange, black and blue) solid line represents the numerical result for modulation amplitude $\xi=0$ ($0.8$, $1.0$, and $1.202$). The dashed horizontal lines mark the maximal efficiencies of the corresponding cases. The red diamond denotes the numerical result of the TC QB. Here $N=8$ and $g/\omega_{0}=1$.
• Figure 4: (a) The contour plot of the efficiency of the QB $\eta(\tau_{\mathrm{c}})$ in the charging process versus the amplitude $\xi$ and Rabi frequency $g$. The initial state of the QB-charger system is $\left|N/2,-N/2\right\rangle _{b}\left|N\right\rangle _{c}$. (b) The contour plot of the mean ergotropy of the QB $\mathcal{E}(\tau_{\mathrm{s}})/N$ versus the amplitude $\xi$ and storage time $\tau_{\mathrm{s}}$ under the energy dissipation noise. The initial state of the QB is $\sum^{N}_{m=0}\left|N/2,-N/2+m\right\rangle _{b}/\sqrt{N+1}$. Here $N=8$, $\omega_{a}/\omega_{0}=\Omega/\omega_{0}=1$, and $\lambda/\omega_{0}=4$.
• Figure 5: (a) The dynamical evolution of the mean ergotropy (left) and coherence (right) of the maximal coherent state $\left|\phi_{1}\right\rangle =\sum^{N}_{m=0}\left|N/2,-N/2+m\right\rangle _{b}/\sqrt{N+1}$ and incoherent state $\left|\phi_{2}\right\rangle =\left|N/2,0\right\rangle _{b}$ under the collective dephasing channel. The solid lines (dotted and dashed lines) represent the results of the state $\left|\phi_{1}\right\rangle$ ($\left|\phi_{2}\right\rangle$). (b) The dynamical evolution of the mean ergotropy of $\left|\phi_{1}\right\rangle$ under the dissipation noise. The blue (green and red) lines describes the result of $\xi=2.404$ ($\xi=1.5$ and $\xi=0$). Here $N=8$, $\gamma/\omega_{0}=2$, $\omega_{a}/\omega_{0}=\Omega/\omega_{0}=1$, and $\lambda/\omega_{0}=4$.