Review of Entanglement Entropy in Non-Hermitian Quantum Many-Body Systems: From Area Laws to Exceptional Criticality

Authors

  • Qingxu Li School of Electronic Science and Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
  • Zhi-Ling Huang School of Electronic Science and Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
  • Jia-Ji Zhu School of Electronic Science and Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400065, China

DOI:

https://doi.org/10.14738/aivp.1402.20241

Abstract

Entanglement entropy serves as a fundamental diagnostic for quantum many-body correlations, distinguishing quantum entanglement from classical stochastic fluctuations. This review systematically explores the scaling behaviors of entanglement entropy, beginning with the foundational area law in Hermitian systems and progressing to the exotic regimes of non-Hermitian physics. We focus on the mathematical apparatus of the Fisher-Hartwig theorem in fermionic chains, the biorthogonal formalism in non-unitary systems, and the emergence of negative entanglement entropy driven by exceptional boundary states and non-unitary conformal field theories.

References

Eisert, J., Cramer, M., & Plenio, M. B. (2010). Collo quium: Area laws for the entanglement entropy. Reviews of Modern Physics, 82(1), 277–306.

Chen, L. M., Zhou, Y., Chen, S. A., & Ye, P. (2024). Quantum entanglement and non-Hermiticity in free-fermion systems. Chinese Physics Letters, 41(12), 127302.

Yi, W. Z., Hai, Y. J., Xiao, R., & Chen, S. (2023). Excep tional entanglement in non-Hermitian fermionic models. arXiv:2304.08609.

Kawabata, K., Numasawa, T., & Ryu, S. (2023). Entan glement phase transition induced by the non-Hermitian skin effect. Physical Review X, 13(2), 021007.

Chang, P. Y., You, J. S., Wen, X., & Ryu, S. (2020). Entanglement spectrum and entropy in topological non Hermitian systems and nonunitary conformal field the ory. Physical Review Research, 2(3), 033069.

Liang, S. D., & Huang, G. Y. (2013). Topological invari ance and global Berry phase in non-Hermitian systems. Physical Review A, 87(1), 012118.

Lieu, S. (2018). Topological phases in the non-Hermitian Su-Schrieffer-Heeger model. Physical Review B, 97(4), 045106.

Xue, W. T., & Lee, C. H. (2026). Topologically protected negative entanglement. Advanced Science, 13(3), e13868.

Plenio, M. B., Eisert, J., Dreißig, J., & Cramer, M. (2005). On the entropy of a quantum harmonic oscillator chain. Physical Review Letters, 94(6), 060503.

Audenaert, K. M. R., Eisert, J., Plenio, M. B., & Werner, R. F. (2002). Physical Review A, 66,

Aharony, O., Gubser, S. S., Maldacena, J., Ooguri, H., & Oz, Y. (2000). Physics Reports, 323,

Korepin, V. E. (2004). Universality of entropy scaling in one-dimensional gapless models. Physical Review Letters, 92(9), 096402.

Its, A. R., Jin, B.-Q., & Korepin, V. E. (2005). Entangle ment in the XY spin chain. Journal of Physics A: Math ematical and General, 38(13), 2975–2990.

Franchini, F., & Abanov, A. G. (2005). Asymptotics of Toeplitz determinants and the entanglement entropy of the XY spin chain. Journal of Physics A: Mathematical and General, 38(23), 5069–5085.

Tu, Y. T., Tzeng, Y. C., & Chang, P. Y. (2022). R´enyi entropies and negative central charges in non-Hermitian quantum systems. SciPost Physics, 12(6), 194.

Cipolloni, G., & Kudler-Flam, J. (2023). Entanglement entropy of non-Hermitian eigenstates and the Ginibre en semble. Physical Review Letters, 130(1), 010401. Scholar Publishing

Fossati, M., Ares, F., & Calabrese, P. (2023). Symmetry resolved entanglement in critical non-Hermitian systems. Physical Review B, 107(20), 205153.

Hastings, M. B. (2004). Lieb-Schultz-Mattis in higher di mensions. Physical Review B, 69(10),

Hastings, M. B. (2007). An area law for one-dimensional quantum systems. Journal of Statistical Mechanics: The ory and Experiment, 2007(08), P08024.

Calabrese, P., & Cardy, J. (2004). Entanglement entropy and quantum field theory. Journal of Statistical Mechan ics: Theory and Experiment, 2004(06), P06002.

Herviou, L., Regnault, N., & Bardarson, J. H. (2019). En tanglement spectrum and symmetries in non-Hermitian fermionic non-interacting models. SciPost Physics, 7(5), 069.

Meden, V., Grunwald, L., & Kennes, D. M. (2023). PT-symmetric, non-Hermitian quantum many body physics—a methodological perspective. Reports on Progress in Physics, 86(12),

Korff, C., & Weston, R. (2007). PT symmetry on the lat tice: the quantum group invariant XXZ spin chain. Jour nal of Physics A: Mathematical and Theoretical, 40(30), 8845–8872.

Couvreur, R., Jacobsen, J. L., & Saleur, H. (2017). Entanglement in Nonunitary Quantum Criti cal Spin Chains. Physical Review Letters, 119, 040601. arXiv:1611.08506.

Chen, L. M., Chen, S. A., & Ye, P. (2021). Entanglement, non-hermiticity, and duality. SciPost Physics, 11(1), 003.

Lee, C. H. (2022). Exceptional bound states and negative entanglement entropy. Physical Review Letters, 128(1), 010402.

Downloads

Published

2026-05-03

How to Cite

Li, Q., Huang, Z.-L., & Zhu, J.-J. (2026). Review of Entanglement Entropy in Non-Hermitian Quantum Many-Body Systems: From Area Laws to Exceptional Criticality. European Journal of Applied Sciences, 14(02), 577–581. https://doi.org/10.14738/aivp.1402.20241