Entanglement of local operators in large-N conformal field theories
Entanglement of local operators in large-N conformal field theories
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DOI：
10.1093/ptep/ptu122
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发表时间：
2014-05
影响因子：
3.5
通讯作者：
Paweł Caputa;M. Nozaki;T. Takayanagi
中科院分区：
文献类型：
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作者：
Paweł Caputa;M. Nozaki;T. Takayanagi
本文研究了大$N$（或大中心电荷）共形场理论中局部算子产生的激发态的Renyi和von Neumann纠缠熵。首先，我们指出一个朴素的大-$N$展开对于冯·诺伊曼纠缠熵可以被打破，而对于Renyi纠缠熵则不能。这种情况甚至发生在自由杨-米尔斯理论的激发态中。其次，我们从场理论和全息的角度分析了强耦合的大$N$ CFTs。我们发现由局域算子产生的激发态的Renyi纠缠熵随时间演化呈对数增长，其系数与局域算子的保形维数成正比。
In this paper, we study Renyi and von Neumann entanglement entropy of excited states created by local operators in large-$N$ (or large-central-charge) conformal field theories (CFTs). First we point out that a naive large-$N$ expansion can break down for the von Neumann entanglement entropy, while it does not for the Renyi entanglement entropy. This happens even for the excited states in free Yang–Mills theories. Next, we analyze strongly coupled large-$N$ CFTs from both the field-theoretic and holographic viewpoints. We find that the Renyi entanglement entropy of the excited state, produced by a local operator, grows logarithmically under its time evolution and its coefficient is proportional to the conformal dimension of the local operator.