Helical Floquet Channels in 1D Lattices

Understand

We show how dispersionless channels exhibiting perfect spin-momentum locking can arise in a 1D lattice model.

• While such spectra are forbidden by fermion doubling in static 1D systems, here we demonstrate their appearance in the stroboscopic dynamics of a periodically driven system.
• Remarkably, this phenomenon does not rely on any adiabatic assumptions, in contrast to the well known Thouless pump and related models of adiabatic spin pumps.
• The proposed setup is shown to be experimentally feasible with state of the art techniques used to control ultracold alkaline earth atoms in optical lattices.