Since the very recent discovery of unconventional superconductivity in twisted WSe2 homobilayers at filling ν = − 1, considerable interest has arisen in revealing its mechanism. In this paper, we developed a three-band tight-binding model with non-trivial band topology by direct Wannierization of the low-energy continuum model. Incorporating both onsite Hubbard repulsion and next-nearest-neighbor attraction, we then performed a mean-field analysis of the microscopic model and obtained a phase diagram qualitatively consistent with the experiment results. For zero or weak displacement field, the ground state is a Chern number C = ± 2 topological superconductor in the Altland-Zirnbauer A-class (breaking time-reversal but preserving total Sz symmetry) with inter-valley pairing dominant in <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="41467_2025_64519_Article_IEq1.gif" Format="GIF" Height="20" Rendition="HTML" Resolution="72" Type="Linedraw" Width="92" /> </InlineMediaObject> <EquationSource Format="TEX">${d}_{xy}\pm i{d}_{{x}^{2}-{y}^{2}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi>d</mi> </mrow> <mrow> <mi>x</mi> <mi>y</mi> </mrow> </msub> <mo>±</mo> <mi>i</mi> <msub> <mrow> <mi>d</mi> </mrow> <mrow> <msup> <mrow> <mi>x</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msup> <mo>−</mo> <msup> <mrow> <mi>y</mi> </mrow> <mrow> <mn>2</mn> </mrow> </msup> </mrow> </msub> </math></EquationSource> </InlineEquation>–wave (mixing with a subdominant px ∓ ipy-wave) component. For a relatively strong displacement field, the ground state is a correlated insulator with the 120° antiferromagnetic order. Our results provide new insights into the nature of the twisted WSe2 systems and suggest the need for further theoretical and experimental explorations.

Theory of topological superconductivity and antiferromagnetic correlated insulators in twisted bilayer WSe₂

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2025年10月28日

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Chuyi Tuo,
Ming-Rui Li,
Zhengzhi Wu,
Wen Sun,
Hong Yao

摘要

Since the very recent discovery of unconventional superconductivity in twisted WSe₂ homobilayers at filling ν = − 1, considerable interest has arisen in revealing its mechanism. In this paper, we developed a three-band tight-binding model with non-trivial band topology by direct Wannierization of the low-energy continuum model. Incorporating both onsite Hubbard repulsion and next-nearest-neighbor attraction, we then performed a mean-field analysis of the microscopic model and obtained a phase diagram qualitatively consistent with the experiment results. For zero or weak displacement field, the ground state is a Chern number C = ± 2 topological superconductor in the Altland-Zirnbauer A-class (breaking time-reversal but preserving total S_z symmetry) with inter-valley pairing dominant in ${d}_{xy}\pm i{d}_{{x}^{2}-{y}^{2}}$ $d_{x y} \pm i d_{x^{2} - y^{2}}$ –wave (mixing with a subdominant p_x ∓ ip_y-wave) component. For a relatively strong displacement field, the ground state is a correlated insulator with the 120° antiferromagnetic order. Our results provide new insights into the nature of the twisted WSe₂ systems and suggest the need for further theoretical and experimental explorations.

Theory of topological superconductivity and antiferromagnetic correlated insulators in twisted bilayer WSe2

摘要

Theory of topological superconductivity and antiferromagnetic correlated insulators in twisted bilayer WSe₂