  Resonant transmission through electronic quantum states that exist at the
zero points of a magnetic field gradient inside a ballistic quantum wire is
reported. Since the semiclassical motion along such a line of zero magnetic
field takes place in form of unidirectional snake trajectories, these states
have no classical equivalence. The existence of such quantum states has been
predicted more than a decade ago by theoretical considerations of Reijniers and
coworkers [1]. We further show how their properties depend on the amplitude of
the magnetic field profile as well as on the Fermi energy.
