Helical Floquet Channels in 1D Lattices

Area of Science:

• Condensed matter physics
• Quantum mechanics
• Atomic physics

Background:

• Static one-dimensional (1D) systems are constrained by fermion doubling, forbidding dispersionless spectra.
• Adiabatic models like the Thouless pump explain spin pumps but require slow driving.
• Periodic driving offers new pathways to engineer quantum phenomena.

Purpose of the Study:

• To demonstrate the emergence of dispersionless channels with perfect spin-momentum locking in a 1D lattice model.
• To explore phenomena beyond the limitations of static systems and adiabatic approximations.
• To propose an experimentally viable setup for realizing these quantum effects.

Main Methods:

• Utilizing a 1D lattice model with periodic driving (stroboscopic dynamics).
• Analyzing the system's spectral properties to identify dispersionless channels.
• Investigating the spin-momentum locking characteristics.
• Proposing an experimental realization using ultracold alkaline earth atoms in optical lattices.

Main Results:

• Dispersionless channels exhibiting perfect spin-momentum locking were shown to arise.
• This phenomenon was observed in the stroboscopic dynamics of a periodically driven system.
• The emergence of these channels was independent of adiabatic assumptions.
• The proposed system was confirmed to be experimentally feasible.

Conclusions:

• Periodic driving enables the realization of exotic quantum states, like dispersionless channels with spin-momentum locking, in 1D systems.
• This approach circumvents limitations imposed by static systems and adiabaticity.
• The findings pave the way for novel quantum simulations and devices using ultracold atoms.