Bulk photogalvanic effects beyond second order

Examining the bulk photogalvanic effect (BPE) at nonperturbative laser fields, it is shown that illuminating a thin noncentrosymmetric crystal, quasicrystal, or nanotube the point group of which is D-n>2, C-(3,C-5,C-...)h, or D-(3,D-5,D-...)h with a monochromatic linearly polarized field, at practically any orientation, induces a nonvanishing directed current component j(z) along its polar axis. This is in contrast to the vanishing j(z) predicted by the commonly employed photogalvanic tensor. Similarly, we discuss the appearance of an angular-dependent j(z), already for C-(n>2)v and C-n>2, and circular dichroism in the BPE that are not resolved in second order. We suggest the possible observation of these currents in, e.g., thin alpha-quartz and LiNbO3:Fe crystals and single-walled chiral carbon nanotubes.