Kaneko Tatsuya, Sun Zhiyuan, Murakami Yuta, Golež Denis, Millis Andrew J
Department of Physics, Columbia University, New York, New York 10027, USA.
Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
Phys Rev Lett. 2021 Sep 17;127(12):127402. doi: 10.1103/PhysRevLett.127.127402.
We investigate the bulk photovoltaic effect, which rectifies light into electric current, in a collective quantum state with correlation driven electronic ferroelectricity. We show via explicit real-time dynamical calculations that the effect of the applied electric field on the electronic order parameter leads to a strong enhancement of the bulk photovoltaic effect relative to the values obtained in a conventional insulator. The enhancements include both resonant enhancements at sub-band-gap frequencies, arising from excitation of optically active collective modes, and broadband enhancements arising from nonresonant deformations of the electronic order. The deformable electronic order parameter produces an injection current contribution to the bulk photovoltaic effect that is entirely absent in a rigid-band approximation to a time-reversal symmetric material. Our findings establish that correlation effects can lead to the bulk photovoltaic effect and demonstrate that the collective behavior of ordered states can yield large nonlinear optical responses.
我们研究了在具有关联驱动电子铁电性的集体量子态中，将光整流为电流的体光伏效应。通过显式实时动力学计算，我们表明外加电场对电子序参量的作用导致体光伏效应相对于传统绝缘体中的值有显著增强。增强包括在子带隙频率处的共振增强，这源于光学活性集体模式的激发，以及由电子序的非共振变形引起的宽带增强。可变形的电子序参量对体光伏效应产生了注入电流贡献，而在时间反演对称材料的刚性带近似中这种贡献完全不存在。我们的发现证实了关联效应可导致体光伏效应，并表明有序态的集体行为可产生大的非线性光学响应。
