的动力学演化图像。当光子数进一步增大时，可以看出，从初始时刻的演化，E
a
与E
b
在第一个波峰已经不能达到它们可以取得的最大值，这是因为此时光子数的作用在演化中的权重进一步上升，在第一个波峰内就已经使D与E
a
、E
b
间的转化中的相当一部分能量变为W。
(a) (b)
Figure 3
. Average photon number n = 0.1: (a) Evolution curve of charger energy (solid line) and battery energy (dotted line); (b) Evolution curves of quantum discord D (solid line) and ergotropy W (dotted line)
图3
. 平均光子数n = 0.1时：(a) 充电器能量(实线)、电池能量(虚线)演化曲线。(b) 量子失协D (实线)、最大功W (虚线)的演化曲线。
图4
(a)是平均光子数
的充电器能量(E
a
)和电池能量(E
b
)随
的动力学演化图像，
图4
(b)是量子失协(QD)和最大功(W)随
的动力学演化图像。当光子数很大时，在系统刚开始演化时，就有很多的光子参与其中，导致E
a
、E
b
可以恢复的是周期内的最小值，这是因为，量子失协所提供的由低能量向高能量传输的动力几乎都变成了系统对外做功的能力。而由于转化回的量子失协越来越少，参与其中的光子数作用也越来越低，导致可供恢复的E
a
、E
b
越来越大，此时(
左右)系统的演化以E
a
、E
b
、W之间的转化为主。但由于参与其中的光子数减少，量子失协恢复的能力增强，此时系统的演化开始向可恢复的失协越来越多，E
a
、E
b
、W的最大值越来越小的方向变化。
(a) (b)
Figure 4
. Average photon number
: (a) Evolution curve of charger energy (solid line) and battery energy (dotted line); (b) Evolution curves of quantum discord D (solid line) and ergotropy W (dotted line)
图4
. 平均光子数
时：(a) 充电器能量(实线)、电池能量(虚线)演化曲线；(b) 量子失协D (实线)、最大功W (虚线)的演化曲线
4. 结论
在本文中，我们将量子电池模型描述为双量子位系统，研究了在不同平均光子数下量子失协对量子电池中能量转换和最大功的影响。从结果可以看出，量子失协是低能力量向高能量充电的动力。光子数很小时，系统几乎没有对外做功的能力，随着平均光子数的增加，电池对外做功的能力越来越强，但是对外做功的能力越强，量子失协对电池电量之间转化的影响就越弱。
文章引用
秦向瑜,徐鸿嘉,刘晓萌,杜燕姣,闫学群. 量子电池中量子失协的作用
The Role of Quantum Discord in Quantum Battery[J]. 现代物理, 2021, 11(06): 119-125.
https://doi.org/10.12677/MP.2021.116015
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NOTES
*
通讯作者。
(a) (b)
(a) (b)