Research

I study many-body quantum systems, frustrated magnets, spin liquids, fractons, and connections to field theory and holography.

Where I am

Current position

I have been an Assistant Professor at the Institute for Solid State Physics, the University of Tokyo, since 2023/10.

Research direction

My work sits at the interface of condensed matter physics, quantum information, and high-energy theory.

Research path

After postdoctoral work at Rice and OIST, I am building a broader theoretical program around spin liquids and fractons.

Research topics

  • How many-body physics, quantum information, and quantum field theory inform each other.
  • Strongly correlated systems, especially frustrated magnets and spin liquids.
  • Fracton states of matter, their links to gravity and holography, and possible realizations.

Classical and quantum spin liquids

I work on classification, low-energy constraints, emergent gauge structures, and spectroscopy of frustrated magnets.

Fractons and holography

I study hyperbolic fracton models, subsystem symmetries, p-adic and AdS/CFT-inspired toy models, and robust quantum memory.

Experimental connections

I am interested in dipole-octupole quantum spin ice, neutron signatures of emergent QED, thermal Hall physics, and material realizations.

Books

  • Lecture Notes on Field Theory for One-Dimensional Quantum Many-Body System

    Ongoing project. Publisher: Springer Nature. In collaboration with Masaki Oshikawa.

  • Chinese Translation of Sidney Coleman's Lectures on Relativity

    Ongoing project. Publisher: Shanghai Scientific & Technical Publishers. In collaboration with Si-Yi Zhou and Jia-Yue Yang.

Preprints

  • Hyperbolic Fracton Model, Subsystem Symmetry and Holography III: Extension to Generic Tessellations

    Yosef Shokeeb, Ludovic D. C. Jaubert, Han Yan. arXiv:2510.25994 [cond-mat.str-el]. PDF.

  • Fragmented Spin Liquid and Shadow Pinch Points in Dipole-Octupole Pyrochlore Spin Systems

    Daniel Lozano-Gomez, Han Yan. arXiv:2509.09205 [cond-mat.str-el]. PDF.

  • Magnetization and magnetostriction measurements of the dipole-octupole quantum spin ice candidate Ce2Hf2O7

    Edwin Kermarrec, Guanyue Chen, Hiromu Okamoto, Chun-Jiong Huang, Han Yan, Jian Yan, Hikaru Takeda, Yusei Shimizu, Evan M. Smith, Avner Fitterman, Andrea D. Bianchi, Bruce D. Gaulin, Minoru Yamashita. arXiv:2509.09189 [cond-mat.str-el]. PDF.

  • Euler topology in classical spin liquids

    Luca Ruegg, Arthur Morris, Han Yan, Robert-Jan Slager. arXiv:2505.09683 [cond-mat.str-el]. PDF.

  • An Atlas of Classical Pyrochlore Spin Liquids

    Daniel Lozano-Gomez, Owen Benton, Michel J. P. Gingras, Han Yan. arXiv:2411.03547 [cond-mat.str-el]. PDF.

  • Zeeman polaritons as a platform for probing Dicke physics in condensed matter

    T. Elijah Kritzell, Jacques Doumani, Tobias Asano, Sota Yamada, Fuyang Tay, Hongjing Xu, Han Yan, Ikufumi Katayama, Jun Takeda, Andriy Nevidomskyy, Hiroyuki Nojiri, Motoaki Bamba, Andrey Baydin, Junichiro Kono. arXiv:2409.17339 [quant-ph]. PDF.

  • Generalized Kramers-Wannier duality from bilinear phase map

    Han Yan, Linhao Li. arXiv:2403.16017 [cond-mat.str-el]. PDF.

  • Experimentally tunable QED in dipolar-octupolar quantum spin ice

    Alaric Sanders, Han Yan, Claudio Castelnovo, Andriy H. Nevidomskyy. arXiv:2312.11641 [cond-mat.str-el]. PDF.

  • Identifying topologically critical band from pinch-point singularities in spectroscopy

    Han Yan. arXiv:2304.02204 [cond-mat.str-el]. PDF.

  • Y-cube model and fractal structure of subdimensional particles on hyperbolic lattices

    Han Yan, Kevin Slagle, Andriy H. Nevidomskyy. arXiv:2211.15829 [cond-mat.str-el]. PDF.

Published papers

2025

  • Conformal Boundary as Holographic Dual to the Hyperbolic Fracton Model

    Alejo Costa Duran, Mauricio Sturla, Ludovic D. C. Jaubert, Han Yan. Phys. Rev. B (Letter) 112, L220401 (2025). arXiv:2411.05662. PDF.

  • Dipolar-octupolar correlations and hierarchy of exchange interactions in Ce2Hf2O7

    Victor Poree, Anish Bhardwaj, Elsa Lhotel, Sylvain Petit, Nicolas Gauthier, Han Yan, Vladimir Pomjakushin, Jacques Ollivier, Jeffrey A. Quilliam, Andriy H. Nevidomskyy, Hitesh J. Changlani, Romain Sibille. Phys. Rev. B (Letter) 112, L180404 (2025). arXiv:2305.08261. PDF.

  • Magnons, Phonons, and Thermal Hall Effect in Candidate Kitaev Magnet alpha-RuCl3

    Shuyi Li, Han Yan, Andriy H. Nevidomskyy. Phys. Rev. B 112, 134413 (2025). arXiv:2301.07401. PDF.

  • p-adic Holography from the Hyperbolic Fracton Model

    Han Yan, Christian B. Jepsen, Yaron Oz. Journal of High Energy Physics 2025, 96 (2025). arXiv:2306.07203. PDF.

  • Human-machine collaboration: ordering mechanism of rank-2 spin liquid on breathing pyrochlore lattice

    Nicolas Sadoune, Ke Liu, Han Yan, Ludovic D. C. Jaubert, Nic Shannon, Lode Pollet. Phys. Rev. Research 7, 033061 (2025). arXiv:2402.10658. PDF.

    Featured on OIST News.

  • Thermodynamics of the dipole-octupole pyrochlore magnet Ce2Hf2O7 in applied magnetic fields

    Anish Bhardwaj, Victor Poree, Han Yan, Nicolas Gauthier, Elsa Lhotel, Sylvain Petit, Jeffrey A. Quilliam, Andriy H. Nevidomskyy, Romain Sibille, Hitesh J. Changlani. Phys. Rev. B 111, 155137 (2025). arXiv:2402.08723. PDF.

  • Classical Z2 spin liquid on the generalized four-color Kitaev model

    Han Yan, Rico Pohle. Phys. Rev. Research (Letter) 7, L012052 (2025). arXiv:2409.04061. PDF.

  • Evidence for fractional matter coupled to an emergent gauge field in a quantum spin ice

    Victor Poree*, Han Yan*, Felix Desrochers*, Sylvain Petit, Elsa Lhotel, Markus Appel, Jacques Ollivier, Yong Baek Kim, Andriy H. Nevidomskyy, Romain Sibille (*co-first author). Nature Physics 21, 83-88 (2025). arXiv:2304.05452. PDF.

    Highlighted in the Journal Club for Condensed Matter Physics.

2024

  • Pinch points and half moons encode Berry curvature

    Han Yan, Andreas Thomasen, Judit Romhanyi, Nic Shannon. Phys. Rev. B 110, 195117 (2024). arXiv:2304.02203. PDF.

  • Classification of Classical Spin Liquids: Topological Quantum Chemistry and Crystalline Symmetry

    Yuan Fang, Jennifer Cano, Andriy H. Nevidomskyy, Han Yan. Phys. Rev. B 110, 054421 (2024). arXiv:2309.12652. PDF.

    Editors' suggestion by Physical Review B.

  • Magnetic properties of the spiral spin liquid and surrounding phases in the square lattice XY model

    Matias G. Gonzalez, Anna Fancelli, Han Yan, Johannes Reuther. Phys. Rev. B 110, 085106 (2024). arXiv:2404.00100. PDF.

  • Classification of Classical Spin Liquids: Typology and Resulting Landscape

    Han Yan, Owen Benton, Roderich Moessner, Andriy H. Nevidomskyy. Phys. Rev. B (Letter) 110, L020402 (2024). arXiv:2305.00155. PDF.

  • Gravitational wave analogues in spin nematics and cold atoms

    Leilee Chojnacki, Rico Pohle, Han Yan, Yutaka Akagi, Nic Shannon. Phys. Rev. B 109, L220407 (2024). arXiv:2310.10078. PDF.

    Editors' suggestion by Physical Review B. Featured on OIST News.

  • Classification of Classical Spin Liquids: Detailed Formalism and Suite of Examples

    Han Yan, Owen Benton, Andriy H. Nevidomskyy, Roderich Moessner. Phys. Rev. B 109, 174421 (2024). arXiv:2305.19189. PDF.

  • Phonon induced rank-2 U(1) nematic liquid states

    Han Yan, Andriy H. Nevidomskyy. Phys. Rev. B 109, 075102 (2024). arXiv:2108.11484. PDF.

2023

  • Beyond single tetrahedron physics of the breathing pyrochlore compound Ba3Yb2Zn5O11

    Rabindranath Bag, Sachith E. Dissanayake, Han Yan, Zhenzhong Shi, David Graf, Eun Sang Choi, Casey Marjerrison, Franz Lang, Tom Lancaster, Yiming Qiu, Wangchun Chen, Stephen J. Blundell, Andriy H. Nevidomskyy, Sara Haravifard. Phys. Rev. B (Letter) 107, L140409 (2023). arXiv:2210.06534. PDF.

  • Evidence for Topological Magnon-Phonon Hybridization in a 2D Antiferromagnet down to the Monolayer Limit

    Jiaming Luo, Shuyi Li, Zhipeng Ye, Rui Xu, Han Yan, Junjie Zhang, Gaihua Ye, Lebing Chen, Ding Hu, Xiaokun Teng, William A. Smith, Boris I. Yakobson, Pengcheng Dai, Andriy H. Nevidomskyy, Rui He, Hanyu Zhu. Nano Letters 23, 2023-2030 (2023).

2022

  • Magnetic field effects in an octupolar quantum spin liquid candidate

    Bin Gao, Tong Chen, Han Yan, Chunruo Duan, Chien-Lung Huang, Xu Ping Yao, Feng Ye, Christian Balz, J. Ross Stewart, Kenji Nakajima, Seiko Ohira-Kawamura, Guangyong Xu, Xianghan Xu, Sang-Wook Cheong, Emilia Morosan, Andriy H. Nevidomskyy, Gang Chen, Pengcheng Dai. Phys. Rev. B 106, 094425 (2022). arXiv:2209.04590. PDF.

  • Low-energy structure of spiral spin liquids

    Han Yan, Johannes Reuther. Phys. Rev. Research 4, 023175 (2022). arXiv:2112.10676. PDF.

  • Sleuthing out exotic quantum spin liquidity in the pyrochlore magnet Ce2Zr2O7

    Anish Bhardwaj, Shu Zhang, Han Yan, Roderich Moessner, Andriy H. Nevidomskyy, Hitesh J. Changlani. npj Quantum Materials 7, 51 (2022). arXiv:2108.01096. PDF.

    Featured on Rice University News.

2021 and Earlier

  • Fracton excitations in classical frustrated kagome spin models

    Max Hering, Han Yan, Johannes Reuther. Phys. Rev. B 104, 064406 (2021). arXiv:2012.08167. PDF.

  • Theory of Ca10Cr7O28 as a bilayer breathing-kagome magnet: Classical thermodynamics and semiclassical dynamics

    Rico Pohle, Han Yan, Nic Shannon. Phys. Rev. B 104, 024426 (2021). arXiv:2103.08790. PDF.

  • Geodesic string condensation from symmetric tensor gauge theory: A unifying framework of holographic toy models

    Han Yan. Phys. Rev. B (Rapid Comm.) 102, 161119(R) (2020). arXiv:1911.01007. PDF.

  • Rank-2 U(1) Spin Liquid on the Breathing Pyrochlore Lattice

    Han Yan, Owen Benton, Ludovic D. C. Jaubert, Nic Shannon. Phys. Rev. Lett. 124, 127203 (2020). arXiv:1902.10934. PDF.

    Editors' suggestion by Physical Review Letters. Highlighted by APS Physics Magazine and Quanta Magazine.

  • Hyperbolic fracton model, subsystem symmetry, and holography. II. The dual eight-vertex model

    Han Yan. Phys. Rev. B 100, 245138 (2019). arXiv:1906.02305. PDF.

  • Identification of emergent constraints and hidden order in frustrated magnets using tensorial kernel methods of machine learning

    Jonas Greitemann, Ke Liu, Ludovic D. C. Jaubert, Han Yan, Nic Shannon, Lode Pollet. Phys. Rev. B 100, 174408 (2019). arXiv:1907.12322. PDF.

    Featured on OIST News.

  • Hyperbolic fracton model, subsystem symmetry, and holography

    Han Yan. Phys. Rev. B 99, 155126 (2019). arXiv:1807.05942. PDF.

    Editors' suggestion by Physical Review B. Featured on OIST News.

  • Half moons are pinch points with dispersion

    Han Yan, Rico Pohle, Nic Shannon. Phys. Rev. B (Rapid Comm.) 98, 140402(R) (2018). arXiv:1806.08520. PDF.

    Editors' suggestion by Physical Review B. Featured on OIST News.

  • Experimental signatures of emergent quantum electrodynamics in Pr2Hf2O7

    Romain Sibille, Nicolas Gauthier, Han Yan, Monica Ciomaga Hatnean, Jacques Ollivier, Barry Winn, Uwe Filges, Geetha Balakrishnan, Michel Kenzelmann, Nic Shannon, Tom Fennell. Nature Physics 14, 711-715 (2018). arXiv:1706.03604. PDF.

    Featured on OIST News and PSI Scientific Highlights.

  • Competing Spin Liquids and Hidden Spin-Nematic Order in Spin Ice with Frustrated Transverse Exchange

    Mathieu Taillefumier, Owen Benton, Han Yan, Ludovic D. C. Jaubert, Nic Shannon. Phys. Rev. X 7, 041057 (2017). arXiv:1705.00148. PDF.

  • Theory of multiple-phase competition in pyrochlore magnets with anisotropic exchange with application to Yb2Ti2O7, Er2Ti2O7, and Er2Sn2O7

    Han Yan, Owen Benton, Ludovic D. C. Jaubert, Nic Shannon. Phys. Rev. B 95, 094422 (2017). arXiv:1603.09466. PDF.

  • A spin-liquid with pinch-line singularities on the pyrochlore lattice

    Owen Benton, Ludovic D. C. Jaubert, Han Yan, Nic Shannon. Nature Communications 7, 11572 (2016). arXiv:1510.01007. PDF.

    Featured on OIST News.

  • WH/ZH production associated with a T-odd (anti)quark at the LHC in next-to-leading order QCD

    Zhang Ren-You, Han Yan, Ma Wen-Gan, Wang Shao-Ming, Guo Lei, Han Liang. Phys. Rev. D 85, 015017 (2012). arXiv:1112.5225. PDF.

  • QCD next-to-leading order predictions to W-pair production in association with a massive (anti)bottom jet at the LHC

    Han Yan, Shao-Ming Wang, Wen-Gan Ma, Ren-You Zhang, Lei Guo. Phys. Rev. D 84, 014009 (2011). arXiv:1106.2890. PDF.

Other articles

  • Neutron scattering signatures of a quantum spin ice

    Romain Sibille, Nicolas Gauthier, Han Yan, Monica Ciomaga Hatnean, Jacques Ollivier, Barry Winn, Uwe Filges, Geetha Balakrishnan, Michel Kenzelmann, Nic Shannon, Tom Fennell. Swiss Neutron News 53, 12-22 (2019). arXiv:1911.00968. PDF.

    Selected as cover article.