Reconfigurable flat bands from cooperative moir\'e and charge order

B. K. Saika; S. Buchberger; S. Mo; A. Rajan; D. Halliday; Y. -C. Yao; L. C. Rhodes; H. Decitre; T. Balasubramanian; C. Polley; P. Wahl; P. D. C. King

arXiv · 2511.05648

Reconfigurable flat bands from cooperative moir\'e and charge order

B. K. Saika·S. Buchberger·S. Mo·A. Rajan·D. Halliday·Y. -C. Yao·L. C. Rhodes·H. Decitre·T. Balasubramanian·C. Polley·P. Wahl·P. D. C. King

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Abstract

The formation of flat electronic bands from long-wavelength superperiodic moir\'e potentials in van der Waals heterostructures underpins the creation and control of a host of highly-tunable correlated and topological phases. While the underlying moir\'e periodicity is typically a fixed property of the heterostructure, here we show how the development of a charge-density wave (CDW) in one of the constituent materials can create an emergent moir\'e lattice. We demonstrate this experimentally in TiSe$_2$/graphite epitaxial heterostructures, using angle-resolved photoemission and scanning-tunnelling microscopy and spectroscopy to directly image the resulting long-wavelength moir\'e potential and concomitant flat-band formation. We show how the intrinsically low-energy, deformable landscape of the CDW imparts significant tunability, stabilising quasi-one-dimensional moir\'e domains from symmetry breaking within the CDW, and allowing the complete suppression of flat-band formation by carrier doping across the CDW phase transition. Our findings thus open a new avenue for engineering moir\'e matter by exploiting the rich many-body states of the parent compounds of 2D heterostructures.

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B. K. Saika, S. Buchberger, S. Mo, A. Rajan, D. Halliday, Y. -C. Yao, L. C. Rhodes, H. Decitre, T. Balasubramanian, C. Polley, P. Wahl, P. D. C. King. 2025-11-07. Reconfigurable flat bands from cooperative moir\'e and charge order. https://arxiv.org/abs/2511.05648

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