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  • Open Access

High-Temperature Phase Separation and Charge-Magnon Liquid in Kinetic Antiferromagnets

Johan Carlström*

  • 1Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
  • 2Department of Physics, KTH, SE-10691 Stockholm, Sweden

  • *Contact author: jcarlst@kth.se
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Phys. Rev. Lett. 135, 106702 – Published 5 September, 2025

DOI: https://doi.org/10.1103/d9c2-yr7j

Abstract

Understanding mechanisms of quantum ordering in strongly correlated systems remains a central challenge in condensed matter physics, with implications for designing novel quantum materials. Here, we investigate kinetic antiferromagnetism on a triangular lattice under an applied magnetic field, where spin polarons emerge as charge-magnon bound states with mutual attraction. Using large-scale diagrammatic Monte Carlo simulations, we show that this interaction drives high-temperature phase separation into charge- and magnon-rich regions, bordered by polarized Mott insulating voids. Spectral function analysis reveals a substantial energy correction from magnon interactions, indicating that these carrier-rich regions form a strongly bound charge-magnon liquid. These findings shed new light on recent experiments on MoTe2/WSe2 moiré bilayers, underscoring kinetic magnetism as a unique pathway for strong intercarrier attraction and high-temperature quantum ordering, with potential applications in quantum materials.

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References (42)

  1. Patrick A. Lee, Naoto Nagaosa, and Xiao-Gang Wen, Doping a Mott insulator: Physics of high-temperature superconductivity, Rev. Mod. Phys. 78, 17 (2006).
  2. P. G. de Gennes, Effects of double exchange in magnetic crystals, Phys. Rev. 118, 141 (1960).
  3. S. Alexandrov and J. T. Devreese, Advances in Polaron Physics (Springer-Verlag, Berlin, Heidelberg, 2010).
  4. A. F. Andreev, Structure of vacancies in solid He3, JETP Lett. 24, 564 (1976).
  5. G. Montambaux, P. Lederer, and M. Heritier, Structure of vacancy induced spin polarons in solid He3, J. Phys. Lett. 40, 499 (1979).
  6. Zhiming Zhang, Yimeng Wang, Kenji Watanabe, Takashi Taniguchi, Keiji Ueno, Emanuel Tutuc, and Brian J. LeRoy, Flat bands in twisted bilayer transition metal dichalcogenides, Nat. Phys. 16, 1093 (2020).
  7. Haining Pan, Fengcheng Wu, and Sankar Das Sarma, Band topology, Hubbard model, Heisenberg model, and Dzyaloshinskii-Moriya interaction in twisted bilayer WSe2, Phys. Rev. Res. 2, 033087 (2020).
  8. Fengcheng Wu, Timothy Lovorn, Emanuel Tutuc, and A. H. MacDonald, Hubbard model physics in transition metal dichalcogenide moiré bands, Phys. Rev. Lett. 121, 026402 (2018).
  9. Yang Xu, Kaifei Kang, Kenji Watanabe, Takashi Taniguchi, Kin Fai Mak, and Jie Shan, A tunable bilayer Hubbard model in twisted WSe2, Nat. Nanotechnol. 17, 934 (2022).
  10. Yosuke Nagaoka, Ferromagnetism in a narrow, almost half-filled s band, Phys. Rev. 147, 392 (1966).
  11. Li Liu, Hong Yao, Erez Berg, Steven R. White, and Steven A. Kivelson, Phases of the infinite u Hubbard model on square lattices, Phys. Rev. Lett. 108, 126406 (2012).
  12. Jan O. Haerter and B. Sriram Shastry, Kinetic antiferromagnetism in the triangular lattice, Phys. Rev. Lett. 95, 087202 (2005).
  13. Johan Carlström, In situ controllable magnetic phases in doped twisted bilayer transition metal dichalcogenides, Phys. Rev. Res. 4, 043126 (2022).
  14. Kyung-Su Kim, Exact hole-induced resonating-valence-bond ground state in certain u=∞ Hubbard models, Phys. Rev. B 107, L140401 (2023).
  15. Shang-Shun Zhang, Wei Zhu, and Cristian D. Batista, Pairing from strong repulsion in triangular lattice Hubbard model, Phys. Rev. B 97, 140507(R) (2018).
  16. Ivan Morera, Márton Kanász-Nagy, Tomasz Smolenski, Livio Ciorciaro, Ataç Imamoǧlu, and Eugene Demler, High-temperature kinetic magnetism in triangular lattices, Phys. Rev. Res. 5, L022048 (2023).
  17. Yang Zhang and Liang Fu, Pseudogap metal and magnetization plateau from doping moiré Mott insulator, SciPost Phys. Core 6, 038 (2023).
  18. Ivan Morera, Annabelle Bohrdt, Wen Wei Ho, and Eugene Demler, Attraction from frustration in ladder systems, Phys. Rev. Res. 6, 023196 (2024).
  19. Zui Tao, Wenjin Zhao, Bowen Shen, Tingxin Li, Patrick Knüppel, Kenji Watanabe, Takashi Taniguchi, Jie Shan, and Kin Fai Mak, Observation of spin polarons in a frustrated moiré Hubbard system, Nat. Phys. 20, 783 (2024).
  20. L. Ciorciaro, T. Smoleński, I. Morera, N. Kiper, S. Hiestand, M. Kroner, Y. Zhang, K. Watanabe, T. Taniguchi, E. Demler, and A. İmamoǧlu, Kinetic magnetism in triangular moiré materials, Nature (London) 623, 509 (2023).
  21. Martin Lebrat, Muqing Xu, Lev Haldar Kendrick, Anant Kale, Youqi Gang, Pranav Seetharaman, Ivan Morera, Ehsan Khatami, Eugene Demler, and Markus Greiner, Observation of Nagaoka polarons in a Fermi–Hubbard quantum simulator, Nature (London) 629, 317 (2024).
  22. Max L. Prichard, Benjamin M. Spar, Ivan Morera, Eugene Demler, Zoe Z. Yan, and Waseem S. Bakr, Directly imaging spin polarons in a kinetically frustrated Hubbard system, Nature (London) 629, 323 (2024).
  23. Muqing Xu, Lev Haldar Kendrick, Anant Kale, Youqi Gang, Geoffrey Ji, Richard T. Scalettar, Martin Lebrat, and Markus Greiner, Frustration- and doping-induced magnetism in a Fermi–Hubbard simulator, Nature (London) 620, 971 (2023).
  24. Yanhao Tang, Lizhong Li, Tingxin Li, Yang Xu, Song Liu, Katayun Barmak, Kenji Watanabe, Takashi Taniguchi, Allan H. MacDonald, Jie Shan, and Kin Fai Mak, Simulation of Hubbard model physics in WSe2/WS2 moiré superlattices, Nature (London) 579, 353 (2020).
  25. Kris Van Houcke, Evgeny Kozik, N. Prokof’ev, and B. Svistunov, Diagrammatic Monte Carlo, Phys. Procedia 6, 95 (2010).
  26. Riccardo Rossi, Determinant diagrammatic Monte Carlo algorithm in the thermodynamic limit, Phys. Rev. Lett. 119, 045701 (2017).
  27. Pengcheng Hou, Tao Wang, Daniel Cerkoney, Xiansheng Cai, Zhiyi Li, Youjin Deng, Lei Wang, and Kun Chen, Feynman diagrams as computational graphs, arXiv:2403.18840.
  28. Kun Chen, Partial renormalization of quasiparticle interactions, arXiv:2404.15844.
  29. R. Rossi, T. Ohgoe, K. Van Houcke, and F. Werner, Resummation of diagrammatic series with zero convergence radius for strongly correlated fermions, Phys. Rev. Lett. 121, 130405 (2018).
  30. Johan Carlström, Spin-charge transformation of lattice fermion models: Duality approach for diagrammatic simulation of strongly correlated systems, J. Phys. Condens. Matter 29, 385602 (2017).
  31. Johan Carlström, Diagrammatic Monte Carlo procedure for the spin-charge transformed Hubbard model, Phys. Rev. B 97, 075119 (2018).
  32. Johan Carlström, Strong-coupling diagrammatic Monte Carlo technique for correlated fermions and frustrated spins, Phys. Rev. B 103, 195147 (2021).
  33. Johan Carlström, Spectral shift technique for strongly correlated lattice fermions, arXiv:2111.05877.
  34. Johan Carlström, Integrating dynamical mean-field theory and diagrammatic Monte Carlo, arXiv:2309.00674.
  35. Johan Carlström, Spectral topology and its relation to Fermi arcs in strongly correlated systems, Phys. Rev. Res. 5, 033160 (2023).
  36. See Supplemental Material at http://link.aps.org/supplemental/10.1103/d9c2-yr7j for technical details.
  37. Emil Blomquist and Johan Carlström, Evidence of attraction between charge carriers in a doped Mott insulator, Phys. Rev. Res. 3, 013272 (2021).
  38. Annabelle Bohrdt, Lukas Homeier, Christian Reinmoser, Eugene Demler, and Fabian Grusdt, Exploration of doped quantum magnets with ultracold atoms, Ann. Phys. (Amsterdam) 435, 168651 (2021), special issue on Philip W. Anderson.
  39. Christian Gross and Immanuel Bloch, Quantum simulations with ultracold atoms in optical lattices, Science 357, 995 (2017).
  40. Joannis Koepsell, Jayadev Vijayan, Pimonpan Sompet, Fabian Grusdt, Timon A. Hilker, Eugene Demler, Guillaume Salomon, Immanuel Bloch, and Christian Gross, Imaging magnetic polarons in the doped Fermi-Hubbard model, Nature (London) 572, 358 (2019).
  41. Joannis Koepsell, Dominik Bourgund, Pimonpan Sompet, Sarah Hirthe, Annabelle Bohrdt, Yao Wang, Fabian Grusdt, Eugene Demler, Guillaume Salomon, Christian Gross, and Immanuel Bloch, Microscopic evolution of doped Mott insulators from polaronic metal to Fermi liquid, arXiv:2009.04440.
  42. Johan Carlström, High-Temperature Phase Separation and Charge-Magnon Liquid in Kinetic Antiferromagnets [Data set] (2025), 10.5281/zenodo.16743143.

Outline

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Phys. Rev. Lett. 135, 106702– Published 5 September, 2025
  • Received 22 January 2025
  • Revised 12 May 2025
  • Accepted 14 July 2025
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