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Flat-band driven Kondo breakdown and reentrant effects in heavy-fermion moiré superlattices

Fabian Eickhoff1,*, Jian-Xin Zhu2,3,†, and Benedikt Fauseweh1,4,‡

  • *Contact author: fabian.eickhoff@dlr.de
  • †Contact author: jxzhu@lanl.gov
  • ‡Contact author: benedikt.fauseweh@tu-dortmund.de
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Phys. Rev. B 113, 235153 – Published 26 June, 2026

DOI: https://doi.org/10.1103/85vr-blw1

Abstract

Moiré superlattices (MSLs) in van der Waals heterostructures have demonstrated their incredible power in driving emergent electronic phenomena, some of which are reminiscent of those usually only observed in bulk strongly correlated quantum materials. With the recent discovery of van der Waals f-electron materials, the design of novel MSLs of intrinsic strong correlation is now within the reach. Here we study the novel electron phases of two-dimensional heavy-fermion MSL with increasingly diluted f-electron local moments. By applying dynamical mean-field theory with numerical renormalization group as an impurity solver, we demonstrate the appearance of a different energy scale and a reentrant Kondo breakdown in connection with the emergence of a flat band in the system. We further compare our numerical findings with predictions derived from the Lieb-Mattis theorem and show the necessity of this energy scale to consistently reconcile the predictions with the conventional single-impurity limit for exceedingly large unit cells.

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Phys. Rev. B 113, 235153– Published 26 June, 2026
  • Received 24 September 2025
  • Revised 27 March 2026
  • Accepted 1 June 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.

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