Band-selective third-harmonic generation in superconducting MgB${}_2$: Possible evidence for Higgs amplitude mode in the dirty limit

Sergey Kovalev, Tao Dong, Li-Yu Shi +13

We report on time-resolved linear and nonlinear terahertz spectroscopy of the two-band superconductor MgB${}_2$ with the superconducting transition temperature $T_c\approx 36$ K. Th…