d+id' Chiral Superconductivity in Bilayer Silicene

TL;DR

This paper predicts that bilayer silicene can host chiral d+id' topological superconductivity driven by spin fluctuations, with tunable properties enabling high critical temperatures.

Contribution

It reveals the potential for bilayer silicene to exhibit chiral d+id' superconductivity mediated by spin fluctuations, a novel topological phase in this material.

Findings

Bilayer silicene is intrinsically metallic with sizable Fermi pockets.

Chiral d+id' topological superconductivity is induced by spin fluctuations.

Strain tuning can optimize superconducting critical temperature.

Abstract

We investigate the structure and physical properties of the undoped bilayer silicene through first-principles calculations and find the system is intrinsically metallic with sizable pocket Fermi surfaces. When realistic electron-electron interaction turns on, the system is identified as a chiral d+id' topological superconductor mediated by the strong spin fluctuation on the border of the antiferromagnetic spin density wave order. Moreover, the tunable Fermi pocket area via strain makes it possible to adjust the spin density wave critical interaction strength near the real one and enables a high superconducting critical temperature.