  Quasi-ballistic semiconductor quantum wires are exposed to localized
perpendicular magnetic fields, also known as magnetic barriers. Pronounced,
reproducible conductance fluctuations as a function of the magnetic barrier
amplitude are observed. The fluctuations are strongly temperature dependent and
remain visible up to temperatures of about 10 K. Simulations based on recursive
Green functions suggest that the conductance fluctuations originate from
parametric interferences of the electronic wave functions which experience
scattering between the magnetic barrier and the electrostatic potential
landscape.
