论文标题
开放量子系统中加速度和温度的量子估计
Quantum estimation of acceleration and temperature in open quantum system
论文作者
论文摘要
在开放的量子系统中，我们研究了两级原子作为与给定环境相互作用的检测器的演变。对于均匀加速的两级原子，在Minkowski真空中耦合到无质量标量场时，当它在一定时间内进化时，我们发现存在量子渔民信息的峰值（QFI）的峰值值（QFI），这表明在选择适当的加速度$ $ $ $ $ $ $ $ $ $ $ $ $时，估计的精确性很高。 QFI对于不同的初始状态参数的$θ$具有不同的行为，显示周期性。但是，周期性随时间的演变而逐渐消失，这意味着初始状态不能影响后来的稳定量子状态。此外，增加了一个边界，我们观察到，当原子接近边界时，QFI的峰值会增加，这表明QFI受边界的保护。在这里，QFI波动，并且可能存在两个峰值，并具有一定的力矩，从而扩大了加速度的检测范围。因此，我们可以通过选择适当的位置和加速度$ a $来提高加速度的估计精度。 QFI相对于初始状态参数$θ$的周期性比以前的无界情况更长，这表明初始状态受边界的保护。最后，对于具有边界的热浴，温度的QFI具有一定时刻的峰值不超过一个峰值，这与边界的加速度QFI不同。该周期性的持续时间比无界情况更长，这表明原子的初始量子状态受两种情况的边界保护。
In an open quantum system, we study the evolution of a two-level atom as a detector which interacts with given environments. For a uniformly accelerated two-level atom coupled to a massless scalar field in the Minkowski vacuum, when it evolves for a certain time, we find that there exists a peak value for the quantum Fisher information (QFI) of acceleration, which indicates that the optimal precision of estimation is achieved when choosing an appropriate acceleration $a$. QFI has different behaviors for different initial state parameters $θ$ of the atom, displaying periodicity. However, the periodicity fades away with the evolution of time, which means that the initial state cannot affect the later stable quantum state. Furthermore, adding a boundary, we observe that the peak value of QFI increases when the atom is close to the boundary, which shows that QFI is protected by the boundary. Here, QFI fluctuates, and there may exist two peak values with a certain moment, which expands the detection range of the acceleration. Therefore, we can enhance the estimation precision of acceleration by choosing an appropriate position and acceleration $a$. The periodicity of QFI with respect to the initial state parameter $θ$ lasts a longer time than the previous unbounded case, which indicates that the initial state is protected by the boundary. Finally, for a thermal bath with a boundary, QFI of temperature has no more than one peak value with a certain moment, which is different from QFI of acceleration with a boundary. The periodicity also lasts a longer time than unbounded case, which shows the initial quantum state of the atom is protected by the boundary for two cases.
