Magnetoresistance of a mesoscopic Ni80Fe20 ring

We studied the magnetoresistance of an individual Ni80Fe20 ring with low-temperature measurements as well as with numerical simulations. In order not to disturb the magnetic states of the ring in the resistance measurements, the ring is contacted via non-magnetic Au contacts. The simulations enable to calculate the change in resistance caused by the anisotropic magnetoresistance effect. The simulations are based on a combination of magnetostatics for the magnetic domain configuration and electrostatics for the electrical current distribution