论文标题
通过量子测量充电
Charging by quantum measurement
论文作者
论文摘要
我们提出了一个量子充电方案，该方案是通过用作一次性充电器的辅助量子位的测量来推动的。一系列相同的Qubits依次耦合到$ n+1 $级别的量子电池，并通过投射操作在联合统一的优化间隔后进行测量。如果以激发状态制备充电器Qubit并以基态进行测量，则可以通过迭代更新优化的测量间隔，将其激发（能量）几乎完美地转移到电池中。从基础状态开始，电池可能会不断充电到更高的能量水平。从热状态开始，当通过测量结果实现种群倒置时，电池还可以通过小于$ n $的测量来实现麦内型和能量的接近单位比率。如果以基态制备充电器Qubit并以激发状态进行测量，则仅通过测量提取的有用工作就可以将电池从热状态转变为成功概率消失之前的高近近腐蚀状态。我们的充电操作比没有测量的操作更有效，并且不会引起电池和充电器的初始连贯性。特别是，我们的发现具有量子测量，以塑造非平衡系统。
We propose a quantum charging scheme fueled by measurements on ancillary qubits serving as disposable chargers. A stream of identical qubits are sequentially coupled to a quantum battery of $N+1$ levels and measured by projective operations after joint unitary evolutions of optimized intervals. If charger qubits are prepared in excited state and measured on ground state, then their excitations (energy) can be near-perfectly transferred to battery by iteratively updating the optimized measurement intervals. Starting from its ground state, the battery could be constantly charged to an even higher energy level. Starting from a thermal state, the battery could also achieve a near-unit ratio of ergotropy and energy through less than $N$ measurements, when a population inversion is realized by measurements. If charger qubits are prepared in ground state and measured on excited state, useful work extracted by measurements alone could transform the battery from a thermal state to a high-ergotropy state before the success probability vanishes. Our operations in charging are more efficient than those without measurements and do not invoke the initial coherence in both battery and chargers. Particularly, our finding features quantum measurement in shaping nonequilibrium systems.
