Time-resolved pump-probe ellipsometry of the photoinduced insulator-metal transition in VO2 nanocrystals

Data available Pseudo dielectric function measured with a time-resolved pump-probe ellipsometry on metamaterial consisting on VO2 NCs embedded in a SiO2 matrix. This metamaterial and its static properties are described in J. John, Y. Gutierrez, Z. Zhang, H. Karl, S. Ramanathan, R. Orobtchouk, F. Moreno, and S. Cueff, "Multipolar Resonances with Designer Tunability Using VO2 Phase-Change Materials," Phys. Rev. Appl. 13, 044053 (2020). The data of the pseudo dielectric function are provided for four different pump fluences. \lambda_{pump} = 500 nm - F_{pump} = 0.6 mJ/cm2 \lambda_{pump} = 500 nm - F_{pump} = 1.7 mJ/cm2 \lambda_{pump} = 500 nm - F_{pump} = 2.5 mJ/cm2 \lambda_{pump} = 500 nm - F_{pump} = 3.0 mJ/cm2 Naming of the files In the .zip file that can be downloaded here, there are several folders. Each are named as lambda_pump_500_nm_fluence_YYY_mJcm-2 YYY is the fluence of the pump. In each folder are two files. pseudoepsilon1.txt- spectral values of the real part of the pseudo dielectric function for the different time delays. pseudoepsilon2.txt- spectral values of the imaginary part of the pseudo dielectric function for the different time delays. Structure of the files Each file has the same structure: The first row an array time delays in picosecond for which measurements have been performed. In the rest of rows, the first element of the array are the photon energy, while the rest of the elements are the values of the dielectric function at each of the elements in the time delay array. Example: time delay t1 t2 t3 ... tn E1(eV) eps1(E1, t1) eps1(E1, t2) eps1(E1, t3) ... eps1(E1, tn) E2(eV) eps1(E2, t1) eps1(E2, t2) eps1(E2, t3) ... eps1(E2, tn) E3(eV) eps1(E3, t1) eps1(E3, t2) eps1(E3, t3) ... eps1(E3, tn) ... ... ... ... ... ... En(eV) eps1(En, t1) eps1(En, t2) eps1(En, t3) ... eps1(En, tn)