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Coexistence of Ferroelectricity and Metallicity in Weakly Coupled (SnSe)1.16(NbSe2) Crystal

Cheng Jia1,2,3,*, Wenyu Huang1,*, Haobo Yang1,2, Chaojie Luo1, Lili Jiang2,4, Shuangxiang Wu1, Ming Li5, Minghui Fan1,5, Yuanjun Yang6 et al.

Hui Zhang1,2,4,†

  • *These authors contributed equally to this work.
  • †Contact author: huiz@ustc.edu.cn
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Phys. Rev. Lett. 135, 236802 – Published 3 December, 2025

DOI: https://doi.org/10.1103/24j9-8g8v

Abstract

Ferroelectric metals, traditionally considered mutually exclusive, face enduring challenges owing to screening effects of itinerant electrons on ferroelectric order. However, in certain van der Waals (vdW) heterostructures, two-dimensional materials with distinct structural and physical properties can be alternatingly arranged in layers, retaining their individual characteristics and thereby enabling the coexistence of ferroelectricity and metallicity. Here, we report the coexistence of robust in-plane ferroelectricity and exceptional metallicity in a natural vdW superlattice (SnSe)1.16(NbSe2) crystal, exhibiting high-density carriers (>1021  cm−3), superconductivity (Tc ∼3.25  K), and Curie temperature up to 383 K. The weak-coupling electronic and phononic natures stabilize in-plane ferroelectricity against screening by high-density carriers, confirming the decoupled electron mechanism. Moreover, we demonstrate the first ferroelectric memristor, where the metallic channel conductance is manipulated through polarization dynamics. Our Letter establishes a universal platform for designing multi-order parameters quantum-confined materials, and opens new avenues for energy-efficient functional electronics.

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Phys. Rev. Lett. 135, 236802– Published 3 December, 2025
  • Received 4 March 2025
  • Revised 22 May 2025
  • Accepted 31 October 2025
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