Theory of topological superconductivity and antiferromagnetic correlated insulators in twisted bilayer WSe<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41152276.
- Also identified by DOI 10.1038/s41467-025-64519-3 and PMC identifier 12569151.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Since the very recent discovery of unconventional superconductivity in twisted WSe<sub>2</sub> 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<sub>z</sub> symmetry) with inter-valley pairing dominant in <math xmlns="http://www.w3.org/1998/Math/MathML"> <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> -wave (mixing with a subdominant p<sub>x</sub> ∓ ip<sub>y</sub>-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 WSe<sub>2</sub> systems and suggest the need for further theoretical and experimental explorations.