Theory of resonantly enhanced photo-induced superconductivity

Abstract

Optical driving of materials has emerged as a versatile tool to control their properties, with photo-induced superconductivity being among the most fascinating examples. In this work, we show that light or lattice vibrations coupled to an electronic interband transition naturally give rise to electron-electron attraction that may be enhanced when the underlying boson is driven into a non-thermal state. We find this phenomenon to be resonantly amplified when tuning the boson's frequency close to the energy difference between the two electronic bands. This result offers a simple microscopic mechanism for photo-induced superconductivity and provides a recipe for designing new platforms in which light-induced superconductivity can be realized. We propose a concrete setup consisting of a graphene-hBN-SrTiO$_3$ heterostructure, for which we estimate a superconducting $T_{\rm c}$ that may be achieved upon driving the system.