Subjecting a nanohelix to a transverse electric field gives rise to superlattice behavior with tunable electronic properties. We theoretically investigate such a system and find Bloch oscillations and negative differential conductance when a longitudinal electric field (along the nanohelix axis) is also applied. Furthermore, we study dipole transitions across the transverse-electric-field-induced energy gap, which can be tuned to the eulogized terahertz frequency range by experimentally attainable external fields. We also reveal a photogalvanic effect by shining circularly polarized light onto our helical quantum wire.
@article{arxiv.1610.04186,
title = {Nanohelices as superlattices: Bloch oscillations and electric dipole transitions},
author = {C. A. Downing and M. G. Robinson and M. E. Portnoi},
journal= {arXiv preprint arXiv:1610.04186},
year = {2016}
}