  We report a novel scheme to generate laser-induced, ultrafast, intense (Tesla
scale), spatially isolated, magnetic fields. Three-dimensional particle-in-cell
simulations show that a femtosecond azimuthally-polarized infrared vector beam,
aimed to a conducting circular aperture, produces an intense axially polarized
tip-shaped femtosecond magnetic field, extending over micrometer distances and
being isolated from the electric field. Our results are backed-up by an
analytic model, demonstrating the underlying physics and guiding for optimal
parameters. In particular, we find the conditions under which the magnetic
nanoprobe is substantially enhanced, reaching 4 T when driven by a $10^{11}$
W/cm$^2$ laser field, which reflects a selective enhancement by a factor of
$\sim$6. Our scheme offers a promising tool to control, probe and tailor
magnetic nanodomains in femtosecond timescales through pure magnetic
interaction by using structured laser beams.
