Understanding resonantly enhanced light-induced superconductivity in K₃C₆₀

Light-induced superconducting-like responses have been observed in K₃C₆₀ when driving with mid-infrared laser pulses [1], with a pronounced 10 THz resonance reported more recently [2]. Here we address the microscopic origin of this resonance. Using numerical calculations on finite clusters for a realistic multi-orbital model of K₃C₆₀ we simulate the effect of a periodic drive on the strongly correlated system. We find a sharp enhancement of pairing correlations when the drive frequency is tuned close to 10 THz, in agreement with experiment. The microscopic origin of this enhancement and its potential implications for a light-induced hidden phase [3] will be discussed. Our results thus provide a microscopic explanation for the resonantly enhanced light-induced superconducting-like state in K₃C₆₀ and strengthen its interpretation as being closely connected to superconducting pairing rather than to purely optical or nonthermal population effects.

[1] Mitrano et al., Nature 530 461–464 (2016).

[2] Rowe et al., Nature Physics 19, 1821–1826 (2023).

[3] Budden et al., Nature Physics 17, 611–618 (2021).