Analytic and geometric properties of photoinduced effects in noncentrosymmetric crystals: photovoltaic current and optical rectification

摘要

An original dispersion relation between the stationary coherent nonlinearoptical responses by current and polarisation is obtained. The dispersionrelation provides a new complimentary tool that can be employed to studylight-induced charge transport models and facilitate experimental dataanalysis. It is shown that the origin of the coherent current and thedc-polarisation induced in a noncentrosymmetric crystal under illumination isrelated to the theory of the Berry phase and can be represented in terms of therenormalised geometric potentials. This renormalisation originates from theextra phase difference acquired by a carrier in the light field on the quantumtransition between the electronic bands. The gauge invariance of thecorresponding expressions for the current and the polarisation is demonstrated.