Tip-induced excitation of a single vortex in nano-size superconductors using scanningtunneling microscopy

Abstract

A single vortex is excited into nano-size Pb superconducting island structures by a localcurrent injection from a probe tip of a scanning tunneling microscope. For theexcitation, a sufficient amount and duration of the pulsed current are required.Injecting the current at peripheral sites is more effective than the center for thevortex excitation. Time-dependent Ginzburg–Landau calculations suggest that acurrent-induced normal-state area, which can be nucleated by the tunneling currentexceeding the critical current and expanded by the Joule heating, reduces the requiredmagnetic field for the vortex penetration and excites a vortex into the islands.