Characterization of material parameters of La0.33Pr0.34Ca0.33MnO3 thin film by terahertz time-domain spectroscopy

We present a systemic study of the terahertz (THz) optical conductivity of a strongly correlated La0.33Pr0.34Ca0.33MnO3 (LPCMO) thin film on a LaAlO3 substrate. The measurements are carried out by THz time-domain spectroscopy in the temperature regime from 15 to 105 K. The frequency-dependent optical conductivity in the metallic phase region of the samples exhibits a non-Drude-like response. We find that below 105 K, both the real and imaginary parts of the complex conductivity can be reproduced by the Drude–Smith model. The important sample and material parameters of the LPCMO thin film (such as the persistence of velocity, the ratio of carrier density to effective mass, and electronic scattering time) can be determined by fitting experimental data. The results obtained agree with those obtained from four-probe electrical transport measurements.