Supplementary Material

The Supplementary Material gives insights into using azimuthally polarized beams to obtain isolated circularly polarized B-fields. Section 1 describes the analytical equations governing the propagation of azimuthally polarized beams in the paraxial approximation. In addition, higher-order vector beams are described and analyzed, demonstrating the suitability of first-order azimuthally polarized beams for generating isolated B-fields. Section 2 solves the Maxwell equations to retrieve the E-field required for obtaining isolated circularly polarized B-fields. The exceedingly complex structure of the retrieved E-fields-a vortex beam polarized along the longitudinal direction-justifies the use of multiple azimuthally polarized beams as a realistic approach to generating isolated circularly polarized B-fields.