Dressel Justin, Chantasri Areeya, Jordan Andrew N, Korotkov Alexander N
Institute for Quantum Studies, Chapman University, Orange, California 92866, USA.
Schmid College of Science and Technology, Chapman University, Orange, California 92866, USA.
Phys Rev Lett. 2017 Dec 1;119(22):220507. doi: 10.1103/PhysRevLett.119.220507.
We investigate the statistical arrow of time for a quantum system being monitored by a sequence of measurements. For a continuous qubit measurement example, we demonstrate that time-reversed evolution is always physically possible, provided that the measurement record is also negated. Despite this restoration of dynamical reversibility, a statistical arrow of time emerges, and may be quantified by the log-likelihood difference between forward and backward propagation hypotheses. We then show that such reversibility is a universal feature of nonprojective measurements, with forward or backward Janus measurement sequences that are time-reversed inverses of each other.
我们研究了由一系列测量所监测的量子系统的时间统计箭头。对于一个连续量子比特测量的例子，我们证明，只要测量记录也被取反，时间反演演化在物理上总是可能的。尽管动力学可逆性得以恢复，但时间的统计箭头仍然出现，并且可以通过正向和反向传播假设之间的对数似然差来量化。然后我们表明，这种可逆性是非投影测量的一个普遍特征，具有相互为时间反演逆的正向或反向雅努斯测量序列。
