论文标题
基塔夫链中非平衡超导状态的动态生成
Dynamic generation of nonequilibrium superconducting states in Kitaev chain
论文作者
论文摘要
当非平衡状态可以表现出相同的宏观特性，例如电导率或超导性，当它们在一段时间内共享可观察到的相同平均值时，它们可以表现出它们。我们通过引入两种订单参数来研究Kitaev链的淬火动力学，这些参数与在动量空间中的两个配对，真实空间中的局部对和BCS样对相关的通道。基于精确的解决方案，我们发现两个阶参数对于基态相同，表明两种配对通道之间的平衡，并且可以识别量子相图。但是，对于通过最初制备的真空状态的时间演化获得的非平衡态，两者是不同的，但两者仍然可以清楚地识别相图。在拓扑非平凡的区域中，非平衡状态更喜欢类似BCS的配对状态。我们的发现提供了一种替代方法，可以从微不足道的空状态下动态生成超导状态，并阐明配对的机理。
Non-equilibrium state can exhibit the same macroscopic properties, such as conductivity or superconductivity, as a static state when they share the identical average of an observable over a period of time. We investigate the quench dynamics of a Kitaev chain by introducing two kinds of order parameters which relate to two channels of pairing, local pair in real space and BCS-like pair in momentum space. Based on exact solutions, we find that two order parameters are identical for the ground state, indicating the balance between two kinds of pairing channels, and can identify the quantum phase diagram. However, for a non-equilibrium state obtained by the time evolution from initially prepared vacuum state, the two are different but both can still clearly identify the phase diagram. In the topologically non-trivial region, the non-equilibrium states prefer the BCS-like pairing state. Our finding provides an alternative way to dynamically generate a superconducting state from a trivial empty state and sheds light on the mechanism of pairing.
