Pseudo-Entropy in Free Quantum Field Theories
Pseudo-Entropy in Free Quantum Field Theories
复制标题
自由量子场论中的伪熵
DOI：
10.1103/physrevlett.126.081601
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发表时间：
2021
影响因子：
8.6
通讯作者：
Wei Zixia
中科院分区：
文献类型：
--
作者：
Mollabashi Ali;Shiba Noburo;Takayanagi Tadashi;Tamaoka Kotaro;Wei Zixia
伪熵是一个有趣的量，具有简单的引力对偶，它将纠缠熵推广为依赖于初始和最终状态。本文通过对二维自由标量场理论和伊辛自旋链的赝熵的数值计算，揭示了量子场论中赝熵的基本性质。我们推广了自由标量理论中赝熵的高斯方法，引入了两个参数：质量和动力学指数。这种计算发现两个新的性质的伪熵，我们猜想是普遍的领域理论，除了面积法行为。另一个是赝熵与平均纠缠熵之差的非正性。此外，我们对伊辛链的数值计算结果表明，赝熵可以作为一个新的量子序参量来检测两个态是否处于相同的量子相位。
Pseudo-entropy is an interesting quantity with a simple gravity dual, which generalizes entanglement entropy such that it depends on both an initial and a final state. Here we reveal the basic properties of pseudo-entropy in quantum field theories by numerically calculating this quantity for a set of two-dimensional free-scalar field theories and the Ising spin chain. We extend the Gaussian method for pseudo-entropy in free-scalar theories with two parameters: massand dynamical exponent. This computation finds two novel properties of pseudo-entropy which we conjecture to be universal in field theories, in addition to an area law behavior. One is a saturation behavior and the other one is nonpositivity of the difference between pseudo-entropy and averaged entanglement entropy. Moreover, our numerical results for the Ising chain imply that pseudo-entropy can play a role as a new quantum order parameter which detects whether two states are in the same quantum phase or not.