Include retardation effects to determine Tc

Develop a finite-frequency (ω ≠ 0) treatment of the screened Coulomb interaction V_{g,g'}(q,iω) in the particle-particle pairing kernel for twisted bilayer WSe2 and determine the resulting superconducting critical temperature Tc, going beyond the static (ω = 0) approximation used to analyze the superconducting instability.

Background

The paper computes superconducting instabilities in twisted bilayer WSe2 using a screened Coulomb interaction obtained within the random phase approximation, but then projects the interaction to its static (ω = 0) component to paper pairing. The authors note that retardation (finite-frequency) effects are important for a faithful estimate of Tc.

Thus, a complete determination of Tc requires incorporating the full frequency dependence of the interaction V(q,iω) in the pairing kernel and solving the resulting gap equation with retardation included.