ArXiv · 2026
Structured light can generate electronic dc currents with azimuthal winding, yet the rules governing their winding order m remain unclear. Here we identify sector-resolved winding selection rules using graphene as a clean two-dimensional platform. By decomposing the current response into local and gradient sectors at the current-operator level, we show that the winding order is determined not by the optical orbital angular momentum ℓ alone, but by the angular structure of the corresponding current operators together with projection onto the azimuthal direction. For scalar Laguerre-Gaussian beams, linear polarization yields m=|ℓ±1| in the local sector and m=|ℓ|,|ℓ±2| in the gradient sector, whereas circular polarization with helicity σ=±1 selects m=|ℓ-σ| in the local sector and m=|ℓ+2σ| in the gradient sector. Numerical time-evolution calculations verify these rules and further show that helicity can select an m=0 branch, producing an azimuthally uniform circulating current whose radial profile determines the axial magnetic field B_z(z). Our results provide a sector-resolved organizing principle for classifying and controlling structured-light-driven dc currents with tailored winding structures.
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