Quantum memory at an eigenstate phase transition in a weakly chaotic model
Quantum memory at an eigenstate phase transition in a weakly chaotic model
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DOI：
10.1103/physreva.106.012206
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发表时间：
2021-12
影响因子：
2.9
通讯作者：
M. Lambert;S. Tsai;S. Kelly
中科院分区：
文献类型：
--
作者：
M. Lambert;S. Tsai;S. Kelly
我们研究了一个与无相互作用自旋的小环境共振耦合的全连接量子自旋模型，并研究了初态性质如何在很长时间内被记忆。除了不被动力学守恒的总能量外，我们还fi和记忆初始态的性质。这种记忆发生在光谱的中间，在那里本征态量子相变(ESQPT)作为能量的函数发生。在频谱能量处记忆ff对系统-环境耦合是健壮的，直到该耦合改变了ESQPT的能量。这项工作证明了ESQPT存储器的ff性质与可积性无关，并提出了这一机制在ESQPT中防止热化的更广泛的一般性。
We study a fully connected quantum spin model resonantly coupled to a small environment of non-interacting spins, and investigate how initial state properties are remembered at long times. We find memory of initial state properties, in addition to the total energy, that are not conserved by the dynamics. This memory occurs in the middle of the spectrum where an eigenstate quantum phase transition (ESQPT) occurs as a function of energy. The memory effect at that energy in the spectrum is robust to system-environment coupling until the coupling changes the energy of the ESQPT. This work demonstrates the effect of ESQPT memory as independent of integrability and suggests a wider generality of this mechanism for preventing thermalization at ESQPTs.