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arXiv · 2509.02185

Tensor renormalization group approach to entanglement entropy

Takahiro Hayazaki·Daisuke Kadoh·Shinji Takeda·Gota Tanaka
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Abstract

We propose a method to compute the entanglement entropy (EE) using the tensor renormalization group (TRG) method. The reduced density matrix of a $d$-dimensional quantum system is represented as a $(d+1)$-dimensional tensor network. We develop an explicit algorithm for $d=1$ that enables the calculation of EE for single-interval subsystems of arbitrary size. We test our method in two-dimensional tensor network of the Ising model. The central charge is obtained as $c=0.49997(8)$ for $D=96$, which agrees with the theoretical prediction within an error, demonstrating the accuracy and reliability of our proposed method.

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Takahiro Hayazaki, Daisuke Kadoh, Shinji Takeda, Gota Tanaka. 2025-09-02. Tensor renormalization group approach to entanglement entropy. https://arxiv.org/abs/2509.02185

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