- Letter
- Open Access
Krylov complexity in mixed phase space
Phys. Rev. D 111, L121902 – Published 16 June, 2025
DOI: https://doi.org/10.1103/gmy7-dn7l
Abstract
We investigate the Krylov complexity of thermofield double states in systems with mixed phase space, uncovering a direct correlation with the Brody distribution, which interpolates between Poisson and Wigner statistics. Our analysis spans two-dimensional random matrix models featuring (I) GOE-Poisson and (II) GUE-Poisson transitions and extends to higher-dimensional cases, including a stringy matrix model (GOE-Poisson) and the mass-deformed SYK model (GUE-Poisson). Krylov complexity consistently emerges as a reliable marker of quantum chaos, displaying a characteristic peak in the chaotic regime that gradually diminishes as the Brody parameter approaches zero, signaling a shift toward integrability. These results establish Krylov complexity as a powerful diagnostic of quantum chaos and highlight its interplay with eigenvalue statistics in mixed phase systems.
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References (85)
- R. C. Hilborn, Chaos and Nonlinear Dynamics: An Introduction for Scientists and Engineers (Oxford University Press, New York, 2000).
- O. Bohigas, M. J. Giannoni, and C. Schmit, Phys. Rev. Lett. 52, 1 (1984).
- O. Bohigas, Phys. Rev. Lett. 52, 1 (1984).
- T. Guhr, A. Muller-Groeling, and H. A. Weidenmuller, Phys. Rep. 299, 189 (1998).
- O. Bohigas and M.-J. Giannoni, Mathematical and Computational Methods in Nuclear Physics (Springer, Berlin, Heidelberg, 2005).
- M. V. Berry, Proc. R. Soc. London 400, 229 (1985).
- S. Muller, S. Heusler, P. Braun, F. Haake, and A. Altland, Phys. Rev. Lett. 93, 014103 (2004).
- A. I. Larkin and Y. N. Ovchinnikov, Sov. Phys. JETP 28, 1200 (1969), http://jetp.ras.ru/cgi-bin/dn/e_028_06_1200.pdf.
- G. P. Berman and G. M. Zaslavsky, Physica (Amsterdam) 91A, 450 (1978).
- J. Maldacena, S. H. Shenker, and D. Stanford, J. High Energy Phys. 08 (2016) 106.
- S. H. Shenker and D. Stanford, J. High Energy Phys. 03 (2014) 067.
- S. H. Shenker and D. Stanford, J. High Energy Phys. 05 (2015) 132.
- A. M. García-García and J. J. M. Verbaarschot, Phys. Rev. D 94, 126010 (2016).
- J. S. Cotler, G. Gur-Ari, M. Hanada, J. Polchinski, P. Saad, S. H. Shenker, D. Stanford, A. Streicher, and M. Tezuka, J. High Energy Phys. 05 (2017) 118; 09 (2018) 2.
- J. de Boer, E. Llabrés, J. F. Pedraza, and D. Vegh, Phys. Rev. Lett. 120, 201604 (2018).
- D. Stanford and E. Witten, Adv. Theor. Math. Phys. 24, 1475 (2020).
- E. Perlmutter, J. High Energy Phys. 10 (2016) 069.
- D. E. Parker, X. Cao, A. Avdoshkin, T. Scaffidi, and E. Altman, Phys. Rev. X 9, 041017 (2019).
- V. Balasubramanian, P. Caputa, J. M. Magan, and Q. Wu, Phys. Rev. D 106, 046007 (2022).
- V. Balasubramanian, J. M. Magan, and Q. Wu, Phys. Rev. E 111, 014218 (2025).
- H. Tang, arXiv:2312.17416.
- P. Caputa, H.-S. Jeong, S. Liu, J. F. Pedraza, and L.-C. Qu, J. High Energy Phys. 05 (2024) 337.
- B. Bhattacharjee and P. Nandy, Phys. Rev. B 111, L060202 (2025).
- H.-S. Jeong, A. Kundu, and J. F. Pedraza, arXiv:2412.12301.
- K. Hashimoto, K. Murata, N. Tanahashi, and R. Watanabe, J. High Energy Phys. 11 (2023) 040.
- H. A. Camargo, V. Jahnke, H.-S. Jeong, K.-Y. Kim, and M. Nishida, Phys. Rev. D 109, 046017 (2024).
- V. Balasubramanian, R. N. Das, J. Erdmenger, and Z.-Y. Xian, J. Stat. Mech. (2025) P033202.
- E. Rabinovici, A. Sánchez-Garrido, R. Shir, and J. Sonner, J. High Energy Phys. 03 (2022) 211.
- G. F. Scialchi, A. J. Roncaglia, and D. A. Wisniacki, Phys. Rev. E 109, 054209 (2024).
- A. Gill, K. Pal, K. Pal, and T. Sarkar, Phys. Rev. B 109, 104303 (2024).
- A. Bhattacharya, P. P. Nath, and H. Sahu, Phys. Rev. D 109, 066010 (2024).
- H. A. Camargo, K.-B. Huh, V. Jahnke, H.-S. Jeong, K.-Y. Kim, and M. Nishida, J. High Energy Phys. 08 (2024) 241.
- G. F. Scialchi, A. J. Roncaglia, C. Pineda, and D. A. Wisniacki, Phys. Rev. E 111, 014220 (2025).
- E. Rabinovici, A. Sánchez-Garrido, R. Shir, and J. Sonner, J. High Energy Phys. 06 (2021) 062.
- B. Bhattacharjee, P. Nandy, and T. Pathak, J. High Energy Phys. 08 (2023) 099.
- N. Hörnedal, N. Carabba, A. S. Matsoukas-Roubeas, and A. del Campo, Commun. Phys. 5, 207 (2022).
- J. Erdmenger, S.-K. Jian, and Z.-Y. Xian, J. High Energy Phys. 08 (2023) 176.
- S. Chapman, S. Demulder, D. A. Galante, S. U. Sheorey, and O. Shoval, Phys. Rev. B 111, 035141 (2025).
- M. Baggioli, K.-B. Huh, H.-S. Jeong, K.-Y. Kim, and J. F. Pedraza, Phys. Rev. Res. 7, 023028 (2025).
- P. Caputa and S. Liu, Phys. Rev. B 106, 195125 (2022).
- M. Afrasiar, J. Kumar Basak, B. Dey, K. Pal, and K. Pal, J. Stat. Mech. (2023) P103101.
- P. Caputa, N. Gupta, S. S. Haque, S. Liu, J. Murugan, and H. J. R. Van Zyl, J. High Energy Phys. 01 (2023) 120.
- K. Pal, K. Pal, A. Gill, and T. Sarkar, Phys. Rev. B 108, 104311 (2023).
- J. Kim, J. Murugan, J. Olle, and D. Rosa, Phys. Rev. A 105, L010201 (2022).
- P. Caputa and K. Kutak, Phys. Rev. D 110, 085011 (2024).
- A. Bhattacharyya, D. Ghosh, and P. Nandi, J. High Energy Phys. 12 (2023) 112.
- B. Bhattacharjee, X. Cao, P. Nandy, and T. Pathak, J. High Energy Phys. 05 (2022) 174.
- K.-B. Huh, H.-S. Jeong, and J. F. Pedraza, J. High Energy Phys. 05 (2024) 137.
- A. Bhattacharya, P. Nandy, P. P. Nath, and H. Sahu, J. High Energy Phys. 12 (2022) 081.
- B. Bhattacharjee, X. Cao, P. Nandy, and T. Pathak, J. High Energy Phys. 03 (2023) 054.
- V. Mohan, J. High Energy Phys. 11 (2023) 222.
- A. Bhattacharya, P. Nandy, P. P. Nath, and H. Sahu, J. High Energy Phys. 12 (2023) 066.
- B. Bhattacharjee, P. Nandy, and T. Pathak, J. High Energy Phys. 01 (2024) 094.
- E. Carolan, A. Kiely, S. Campbell, and S. Deffner, Europhys. Lett. 147, 38002 (2024).
- A. Bhattacharyya, S. S. Haque, G. Jafari, J. Murugan, and D. Rapotu, J. High Energy Phys. 10 (2023) 157.
- P. Nandy, A. S. Matsoukas-Roubeas, P. Martínez-Azcona, A. Dymarsky, and A. del Campo, Phys. Rep. 1125, 1 (2025).
- T. A. Brody, Lett. Nuovo Cimento Soc. Ital. Fis. 7, 482 (1973).
- T. A. Brody, Rev. Mod. Phys. 53, 385 (1981).
- C. Lanczos, J. Res. Natl. Bur. Stand. B 45, 255 (1950).
- V. S. Viswanath and G. Müller, The Recursion Method: Application to Many-Body Dynamics (Springer, Berlin, Heidelberg, Germany, 1994).
- M. A. Jafarizadeh, N. Fouladi, H. Sabri, and B. R. Maleki, arXiv:1210.4751.
- H. Sabri and N. Fouladi, Eur. Phys. J. Plus 129, 124 (2014).
- J. Nieminen and L. Muche, Acta Phys. Pol. B 48, 765 (2017).
- D. E. Berenstein, J. M. Maldacena, and H. S. Nastase, J. High Energy Phys. 04 (2002) 013.
- T. Banks, W. Fischler, S. H. Shenker, and L. Susskind, Phys. Rev. D 55, 5112 (1997).
- P. Amore, L. A. Pando Zayas, J. F. Pedraza, N. Quiroz, and C. A. Terrero-Escalante, arXiv:2407.07259.
- See Supplemental Material at http://link.aps.org/supplemental/10.1103/gmy7-dn7l for details on the level spacing statistics.
- X.-Y. Song, C.-M. Jian, and L. Balents, Phys. Rev. Lett. 119, 216601 (2017).
- A. Eberlein, V. Kasper, S. Sachdev, and J. Steinberg, Phys. Rev. B 96, 205123 (2017).
- A. M. García-García, B. Loureiro, A. Romero-Bermúdez, and M. Tezuka, Phys. Rev. Lett. 120, 241603 (2018).
- Y.-Z. You, Phys. Rev. B 95, 115150 (2017).
- C. Krishnan, K. V. Pavan Kumar, and D. Rosa, J. High Energy Phys. 01 (2018) 064.
- Y.-Z. You, A. W. W. Ludwig, and C. Xu, Phys. Rev. B 95, 115150 (2017).
- T. Nosaka, D. Rosa, and J. Yoon, J. High Energy Phys. 09 (2018) 041.
- J. Kim and X. Cao, Phys. Rev. Lett. 126, 109101 (2021).
- A. M. García-García, B. Loureiro, A. Romero-Bermúdez, and M. Tezuka, Phys. Rev. Lett. 126, 109102 (2021).
- A. V. Lunkin, A. Y. Kitaev, and M. V. Feigel’man, Phys. Rev. Lett. 125, 196602 (2020).
- D. K. Nandy, T. Cadez, B. Dietz, A. Andreanov, and D. Rosa, Phys. Rev. B 106, 245147 (2022).
- H. G. Menzler and R. Jha, Phys. Rev. B 110, 125137 (2024).
- E. Cáceres, A. Misobuchi, and A. Raz, J. High Energy Phys. 08 (2022) 236.
- P. Orman, H. Gharibyan, and J. Preskill, J. High Energy Phys. 02 (2025) 173.
- A. M. García-García, Y. Jia, D. Rosa, and J. J. Verbaarschot, Phys. Rev. D 103, 106002 (2021).
- E. Cáceres, T. Guglielmo, B. Kent, and A. Misobuchi, J. High Energy Phys. 11 (2023) 088.
- A. M. García-García, C. Liu, and J. J. M. Verbaarschot, Phys. Rev. Lett. 133, 091602 (2024).
- K. Hashimoto, K.-B. Huh, K.-Y. Kim, and R. Watanabe, J. High Energy Phys. 11 (2020) 068.