Fig. 2

(a) Resistivity versus temperature (\(\:\rho\:\left(\varTheta\:\right)\)) for an AlOx w = 20 μm sample. In blue circles are the data for the pristine device, while in violet triangles are the data after annealing at 150 °C for approximately 8 h in an Ar environment. (b) Resistivity versus temperature (\(\:\rho\:\left(\varTheta\:\right)\)) for a Hi-Res Si w = 20 μm sample in a perpendicular magnetic field (B). In gray exes are the data in zero magnetic field, while in orange pluses are the data in a perpendicular magnetic field of 0.77 T. The arrows indicate the temperature direction and the numbers the temporal sequence (in order from darker to lighter).