Topological Chiral Superconductivity Mediated by Intervalley Antiferromagnetic Fluctuations in Twisted Bilayer WSe2

Abstract

Motivated by the recent observations of superconductivity in twisted bilayer WSe2 (tWSe2), we theoretically investigate the superconductivity driven by an electronic mechanism. We first demonstrate that the multiband screened Coulomb interaction within the random phase approximation is insufficient to induce observable pairing instability. Nevertheless, by further including the intervalley antiferromagnetic fluctuations, the pairing interaction is substantially enhanced, yielding superconductivity with critical temperature Tc of hundreds of millikelvin at Van Hove singularities. The predicted Tc increases with increasing the displacement field and corresponds to a doubly degenerate d-wavelike pairing, which evolves into a topological chiral d±id superconductor below Tc. The interplay between superconductivity and intervalley antiferromagnetism results in a phase diagram consistent with experimental observations. These findings provide strong support for intervalley fluctuations as the primary pairing glue in tWSe2.

Source-reported materials — not catalogue approval

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