  Free electron beams that carry high values of orbital angular momentum (OAM)
possess large magnetic moments along the propagation direction. This makes them
an ideal probe for measuring the electronic and magnetic properties of
materials, and for fundamental experiments in magnetism. However, their
generation requires the use of complex diffractive elements, which usually take
the form of nano-fabricated holograms. Here, we show how the limitations of
focused ion beam milling in the fabrication of such holograms can be overcome
by using electron beam lithography. We demonstrate experimentally the
realization of an electron vortex beam with the largest OAM value that has yet
been reported (L = 1000h\bar), paving the way for even more demanding
demonstrations and applications of electron beam shaping.
