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Thermoelectricity of Moiré Heavy Fermions in MoTe2/WSe2 Bilayers

Yichi Zhang1,*, Wenjin Zhao2,*, Zhongdong Han1, Kenji Watanabe3, Takashi Taniguchi3, Jie Shan1,2,4,5,†, and Kin Fai Mak1,2,4,5,‡

  • *These authors contributed equally to this work.
  • †Contact author: jie.shan@mpsd.mpg.de
  • ‡Contact author: kin-fai.mak@mpsd.mpg.de
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Phys. Rev. Lett. 136, 186501 – Published 6 May, 2026

DOI: https://doi.org/10.1103/1qvv-2vrw

Abstract

Tunable Kondo lattice and heavy fermion physics have been recently reported in moiré materials, but most of the studies have focused on the electrical and magnetic properties. Quantitative thermoelectric measurements, which can reveal entropic information of the heavy fermions, have yet to be achieved. Here, we report a comprehensive thermoelectric study on the moiré heavy fermion phase realized in hole-doped angle-aligned MoTe2/WSe2 bilayers. By electrically gating the material to the Kondo lattice region of the phase diagram, we observe a sign change in the Seebeck coefficient near the Kondo coherence temperature, where the heavy fermion phase with an electronlike Fermi surface evolves into an itinerant Fermi liquid with a holelike Fermi surface. We compare the results with the semiclassical Mott relation and discuss the observed discrepancies. In addition to the thermal dissociation of Kondo singlets in the heavy Fermi liquid, a sign change accompanied by a strong peak in the Seebeck coefficient is also observed near a Zeeman breakdown of the Kondo singlets, signaling an entropy accumulation. Our results provide entropic information on both the formation and breakdown of heavy fermions in moiré semiconductors.

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References (67)

  1. Z.-D. Song and B. A. Bernevig, Magic-angle twisted bilayer graphene as a topological heavy fermion problem, Phys. Rev. Lett. 129, 047601 (2022).
  2. R. L. Merino, D. Călugăru, H. Hu, J. Díez-Mérida, A. Díez-Carlón, T. Taniguchi, K. Watanabe, P. Seifert, B. Andrei Bernevig, and D. K. Efetov, Interplay between light and heavy electron bands in magic-angle twisted bilayer graphene, Nat. Phys. 21, 1078 (2025).
  3. S. B. Porro et al., Cryo-near-field photovoltage microscopy of heavy-fermion twisted symmetric trilayer graphene, arXiv:2402.12296.
  4. W. Zhao, B. Shen, Z. Tao, Z. Han, K. Kang, K. Watanabe, T. Taniguchi, K. F. Mak, and J. Shan, Gate-tunable heavy fermions in a moiré Kondo lattice, Nature (London) 616, 61 (2023).
  5. W. Zhao et al., Emergence of ferromagnetism at the onset of moiré Kondo breakdown, Nat. Phys. 20, 1772 (2024).
  6. W. Zhao et al., Emergence of Chern metal in a moiré Kondo lattice, arXiv:2506.14063.
  7. Z. Han, Y. Xia, Z. Xia, W. Zhao, Y. Zhang, K. Watanabe, T. Taniguchi, J. Shan, and K. F. Mak, Evidence of topological Kondo insulating state in MoTe2/WSe2 moiré bilayers, arXiv:2507.03287.
  8. H. B. Callen, The application of onsager’s reciprocal relations to thermoelectric, thermomagnetic, and galvanomagnetic effects, Phys. Rev. 73, 1349 (1948).
  9. H. B. Callen, A note on the adiabatic thermomagnetic effects, Phys. Rev. 85, 16 (1952).
  10. X. Deng, J. Mravlje, R. Žitko, M. Ferrero, G. Kotliar, and A. Georges, How bad metals turn good: Spectroscopic signatures of resilient quasiparticles, Phys. Rev. Lett. 110, 086401 (2013).
  11. K. Behnia, Fundamentals of Thermoelectricity (Oxford University Press, New Yok, 2015).
  12. K. Behnia, What is measured when measuring a thermoelectric coefficient?, C.R. Phys. 23, 25 (2023).
  13. A. K. Paul et al., Interaction-driven giant thermopower in magic-angle twisted bilayer graphene, Nat. Phys. 18, 691 (2022).
  14. T. Song et al., Unconventional superconducting quantum criticality in monolayer WTe2, Nat. Phys. 20, 269 (2024).
  15. N. Sultana, R. W. Rienstra, K. Watanabe, T. Taniguchi, J. A. Stroscio, N. B. Zhitenev, D. E. Feldman, and F. Ghahari, Detection of fractional quantum Hall states by entropy-sensitive measurements, Nat. Phys. 21, 724 (2025).
  16. B. Ghawri et al., Breakdown of semiclassical description of thermoelectricity in near-magic angle twisted bilayer graphene, Nat. Commun. 13, 1522 (2022).
  17. Z. A. Xu, N. P. Ong, Y. Wang, T. Kakeshita, and S. Uchida, Vortex-like excitations and the onset of superconducting phase fluctuation in underdoped La2-xSrxCuO4, Nature (London) 406, 486 (2000).
  18. Y. Wang, L. Li, and N. P. Ong, Nernst effect in high-Tc superconductors, Phys. Rev. B 73, 024510 (2006).
  19. A. Bentien, S. Johnsen, G. K. H. Madsen, B. B. Iversen, and F. Steglich, Colossal Seebeck coefficient in strongly correlated semiconductor FeSb2, Europhys. Lett. 80, 17008 (2007).
  20. U. Köhler, N. Oeschler, F. Steglich, S. Maquilon, and Z. Fisk, Energy scales of Lu1–xYbxRh2Si2 by means of thermopower investigations, Phys. Rev. B 77, 104412 (2008).
  21. P. Sun and F. Steglich, Nernst effect: Evidence of local Kondo scattering in heavy fermions, Phys. Rev. Lett. 110, 216408 (2013).
  22. G. R. Stewart, Heavy-fermion systems, Rev. Mod. Phys. 56, 755 (1984).
  23. S. Kirchner, S. Paschen, Q. Chen, S. Wirth, D. Feng, J. D. Thompson, and Q. Si, Colloquium: Heavy-electron quantum criticality and single-particle spectroscopy, Rev. Mod. Phys. 92, 011002 (2020).
  24. S. Paschen and Q. Si, Quantum phases driven by strong correlations, Nat. Rev. Phys. 3, 9 (2020).
  25. See Supplemental Material at http://link.aps.org/supplemental/10.1103/1qvv-2vrw, which includes Refs. [26–32], for details of the materials and methods, device simulation, temperature gradient calibration, theoretical models, discussions and additional data.
  26. L. Wang et al., One-dimensional electrical contact to a two-dimensional material, Science 342, 614 (2013).
  27. L. Duclaux, B. Nysten, J. P. Issi, and A. W. Moore, Structure and low-temperature thermal conductivity of pyrolytic boron nitride, Phys. Rev. B 46, 3362 (1992).
  28. A. Pisoni, J. Jacimovic, R. Gaál, B. Náfrádi, H. Berger, Z. Révay, and L. Forró, Anisotropic transport properties of tungsten disulfide, Scr. Mater. 114, 48 (2016).
  29. G. A. Slack, Thermal conductivity of pure and impure silicon, silicon carbide, and diamond, J. Appl. Phys. 35, 3460 (1964).
  30. M. Dutta and H. E. Jackson, Low-temperature thermal conductivity of amorphous silica, Phys. Rev. B 24, 2139 (1981).
  31. Y. Liu et al., Thermal conductance of the 2D MoS2/h-BN and graphene/h-BN interfaces, Sci. Rep. 7, 43886 (2017).
  32. P. Středa and L. Smrčka, Galvanomagnetic effects in alloys in quantizing magnetic fields, Phys. Status Solidi (b) 70, 537 (1975).
  33. W. Zhao et al., Realization of the Haldane Chern insulator in a moiré lattice, Nat. Phys. 20, 275 (2024).
  34. T. Li et al., Quantum anomalous Hall effect from intertwined moiré bands, Nature (London) 600, 641 (2021).
  35. Y. Zhang, T. Devakul, and L. Fu, Spin-textured Chern bands in AB-stacked transition metal dichalcogenide bilayers, Proc. Natl. Acad. Sci. U.S.A. 118, e2112673118 (2021).
  36. T. Devakul and L. Fu, Quantum anomalous Hall effect from inverted charge transfer gap, Phys. Rev. X 12, 021031 (2022).
  37. D. Guerci, K. P. Lucht, V. Crépel, J. Cano, J. H. Pixley, and A. Millis, Topological Kondo semimetal and insulator in AB-stacked heterobilayer transition metal dichalcogenides, Phys. Rev. B 110, 165128 (2024).
  38. F. Xie, L. Chen, and Q. Si, Kondo effect and its destruction in heterobilayer transition metal dichalcogenides, Phys. Rev. Res. 6, 013219 (2024).
  39. D. Guerci, J. Wang, J. Zang, J. Cano, J. H. Pixley, and A. Millis, Chiral Kondo lattice in doped MoTe2/WSe2 bilayers, Sci. Adv. 9, eade7701 (2023).
  40. F. Wu, T. Lovorn, E. Tutuc, and A. H. Macdonald, Hubbard model physics in transition metal dichalcogenide moiré bands, Phys. Rev. Lett. 121, 026402 (2018).
  41. Y. Tang et al., Simulation of Hubbard model physics in WSe2/WS2 moiré superlattices, Nature (London) 579, 353 (2020).
  42. E. C. Regan et al., Mott and generalized Wigner crystal states in WSe2/WS2 moiré superlattices, Nature (London) 579, 359 (2020).
  43. K. F. Mak and J. Shan, Semiconductor moiré materials, Nat. Nanotechnol. 17, 686 (2022).
  44. A. Dalal and J. Ruhman, Orbitally selective Mott phase in electron-doped twisted transition metal-dichalcogenides: A possible realization of the Kondo lattice model, Phys. Rev. Res. 3, 043173 (2021).
  45. A. Kumar, N. C. Hu, A. H. Macdonald, and A. C. Potter, Gate-tunable heavy fermion quantum criticality in a moiré Kondo lattice, Phys. Rev. B 106, L041116 (2022).
  46. H. V. Löhneysen, A. Rosch, M. Vojta, and P. Wölfle, Fermi-liquid instabilities at magnetic quantum phase transitions, Rev. Mod. Phys. 79, 1015 (2007).
  47. Y. M. Zuev, W. Chang, and P. Kim, Thermoelectric and magnetothermoelectric transport measurements of graphene, Phys. Rev. Lett. 102, 096807 (2009).
  48. J. G. Checkelsky and N. P. Ong, Thermopower and Nernst effect in graphene in a magnetic field, Phys. Rev. B 80, 081413(R) (2009).
  49. S. M. Girvin and M. Jonson, Inversion layer thermopower in high magnetic field, J. Phys. C 15, L1147 (1982).
  50. M. Jonson and S. M. Girvin, Thermoelectric effect in a weakly disordered inversion layer subject to a quantizing magnetic field, Phys. Rev. B 29, 1939 (1984).
  51. D. L. Bergman and V. Oganesyan, Theory of dissipationless Nernst effects, Phys. Rev. Lett. 104, 066601 (2010).
  52. M. Cutler and N. F. Mott, Observation of Anderson localization in an electron gas, Phys. Rev. 181, 1336 (1969).
  53. S.-G. Nam, D.-K. Ki, and H.-J. Lee, Thermoelectric transport of massive Dirac fermions in bilayer graphene, Phys. Rev. B 82, 245416 (2010).
  54. G. Grosso and G. P. Parravicini, in Solid State Physics (Elsevier, New York, 2000), p. 389.
  55. M. W. Wu, N. J. M. Horing, and H. L. Cui, Phonon-drag effects on thermoelectric power, Phys. Rev. B 54, 5438 (1996).
  56. S. V. Koniakhin and E. D. Eidelman, Phonon drag thermopower in graphene in equipartition regime, Europhys. Lett. 103, 37006 (2013).
  57. P. Coleman, Heavy fermions and the Kondo lattice: A 21st century perspective, arXiv:1509.05769.
  58. D. Jaccard, A. Basset, J. Sierro, and J. Pierre, Thermpower of CexY1-xInCu2 and CeInCuyAg2-y, J. Low Temp. Phys. 80, 285 (1990).
  59. U. Gottwick, K. Gloss, S. Horn, F. Steglich, and N. Grewe, Transport coefficients of intermediate valent CeNix intermetallic compounds, J. Magn. Magn. Mater. 47–48, 536 (1985).
  60. D. Jaccard, J. Flouquet, and J. Sierro, Two-band model and ground state of heavy fermion compounds, J. Appl. Phys. 57, 3084 (1985).
  61. C. S. Garde and J. Ray, Thermopower and resistivity behavior in Ce-based Kondo-lattice systems: A phenomenological approach, Phys. Rev. B 51, 2960 (1995).
  62. D. Călugăru, H. Hu, R. L. Merino, N. Regnault, D. K. Efetov, and B. A. Bernevig, The thermoelectric effect and its natural heavy fermion explanation in twisted bilayer and trilayer graphene, arXiv:2402.14057.
  63. Y. Yang et al., Anomalous enhancement of the Nernst effect at the crossover between a Fermi liquid and a strange metal, Nat. Phys. 19, 379 (2023).
  64. D. Kaczorowski and A. Ślebarski, Kondo lattice behavior and magnetic ordering in CeRh2Si, Phys. Rev. B 81, 214411 (2010).
  65. S. Tsuda et al., Metamagnetic crossover in the quasikagome Ising Kondo-lattice compound CeIrSn, Phys. Rev. B 98, 155147 (2018).
  66. W. Zhou et al., Kondo behavior and metamagnetic phase transition in the heavy-fermion compound CeBi2, Phys. Rev. B 97, 195120 (2018).
  67. Z. Hossain, L. C. Gupta, and C. Geibel, Magnetic transition in the Kondo lattice system CeRhSn2, J. Phys. Condens. Matter 14, 9687 (2002).

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Phys. Rev. Lett. 136, 186501– Published 6 May, 2026
  • Received 26 October 2025
  • Revised 15 January 2026
  • Accepted 31 March 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by the Max Planck Society.

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