[21p-P1-1~15] 3.12 Nanoscale optical science and near-field optics

[21p-P1-14] Theoretical method for infrared absorption of arbitral electric field

〇Takeshi Iwasa^1,2, Masato Takenaka¹, Tetsuya Taketsugu^1,2 (1.Hokkaido Univ., 2.Kyoto ESICB)

Keywords:near field infrared absorption spectroscopy,Electronic structure methods,Multipolar Hamiltonian

Recent advances in infrared spectroscopy and microscopy using near-fields allow us to study dipole-forbidden excitations or observe local vibrational properties, but also require us to deal with non-uniform electric fields for analysis and understandings. In this study, we propose a theoretical method that is beyond the dipole approximation. The method is based on the multipolar Hamiltonian and arbitrary electric field can be considered for obtaining IR absorption spectra.