  The elucidation of the mechanisms behind chiral-induced spin selectivity
remains an outstanding scientific challenge. Here we consider the role of
delocalised phonon modes in electron transport in chiral structures and
demonstrate that spin selectivity can originate from spin-dependent energy and
momentum conservation in electron-phonon scattering events. While this
mechanism is robust to the specifical nature of the vibrational modes, the
degree of spin polarization depends on environmental factors, such as external
driving fields, temperatures and phonon relaxation rates. This dependence is
used to present experimentally testable predictions of our model.
