2.

Imaging of the transverse component of Lorentz force of optical near-field generated on the surface of a tungsten nanotip by coherent optical excitation. (a) Maximum of the measured y-component of the transverse momentum change of the electrons Δp _y and (c) its x-component Δp _x compared to the numerical results shown in (b, d). (e) Comparison of the measured (black curve) and the calculated (red curve) spatial profiles of Δp _y obtained by integrating the data in the region marked by dashed lines in (a, b). (f) Maximum of the total transverse momentum change of the electrons Δp _⊥ induced by the near-field of a blunter tip with larger radius of curvature of the apex. Panels (a–e) use the same scale.