Field-induced p-wave superconducting state of mesoscopic systems.

By using Bogoliubov-de Gennes equations, we study superconducting (SC) states in a quasi-two-dimensional system of radius R. It is shown that no vortices exist in s-wave SC samples with R < R(c) ~ ξ(0), the T = 0 coherence length. We predict that chiral p-wave states exhibit superconductivity for R < R(c) only in the presence of a vortex with opposite chirality. This induced SC phase is a consequence of nonzero chirality of the pairing order parameter and implies the presence of chiral edge currents. Our study may be applied to sharply probing the pairing symmetry of unconventional superconductors.