2025/08/21 by Takahiro Morimoto, Naoto Nagaosa, Morimoto, Takahiro +1
Materials Science · Physics and Astronomy · #Organic and Molecular Conductors Research #Quantum and electron transport phenomena #Advanced Materials and Semiconductor Technologies
paper · pdf · doi:10.48550/arxiv.2508.15347
We study bulk photovoltaic effects in electron-phonon coupled systems. The conservation of current or gauge invariance, manifested as the Ward-Takahashi identity, plays an essential role in the analysis of the Feynman diagrams, and the leading order contribution to the phonon shift current is identified accordingly. The leading order contribution essentially arises from the electric polarization carried by optically excited phonons, where the shift current is generated due to a change of electric polarization in the steady state under the optical excitation of phonons.