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arXiv · 2208.09545

Ballistic photocurrent driven by optical phonon modes in a polaronic ferroelectric

Sangeeta Rajpurohit·Tadashi Ogitsu·Liang Z. Tan
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Abstract

We investigate the effect of local electron-phonon coupling on nonlinear optical conductivity in an interacting ferroelectric system. Using real-time simulations, we show an enhancement in nonlinear conductivity under linearly-polarized light due to generation of the phonon-assisted ballistic-current in addition to the injection-current generated by electron-hole pairs. The optically excited phonon modes generate an asymmetric carrier distribution that causes a strong directional ballistic-current. The ballistic-current enhances the photocurrent several times at above band-gap excitation frequencies and is sublinearly dependent on the excitation intensity. This strong phonon-assisted zero-frequency directional ballistic-current demonstrates an alternative way to boost the bulk photovoltaic effect (BPVE) in electronic ferroelectric materials with strong local electron-phonon coupling.

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Sangeeta Rajpurohit, Tadashi Ogitsu, Liang Z. Tan. 2022-08-19. Ballistic photocurrent driven by optical phonon modes in a polaronic ferroelectric. https://arxiv.org/abs/2208.09545

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