Bloch Oscillations & Wannier-Stark Ladders

AC-driven tight-binding lattice — Floquet theory

Parameters

H = -J Σ(c†ₙ₊₁cₙ + h.c.)
+ F·n + A·cos(ωt)·n
ε(k) = -2J cos(ka)
T_B = 2π/(Fa)
Wannier-Stark ladder:
Eₘ = E₀ + m·Fa
Floquet: J_eff = J·J₀(A/ω)
In a DC field, an electron oscillates in momentum space (Bloch period T_B). AC driving renormalizes hopping via Bessel function J₀(A/ω) — dynamic localization when J₀=0 (A/ω ≈ 2.405).