ИСТИНА

Vortices in quantum condensates exist owing to a macroscopic phase coherence. We show, both experimentally and theoretically, that a quantum vortex with a well-defined core can exist in a rather thick normal metal proximized with a superconductor. Using scanning tunnelling spectroscopy we reveal a proximity vortex lattice at the surface of 50 nm thick Cu-layer deposited on Nb. We demonstrate that these vortices have regular round cores in the centres of which the proximity mini gap vanishes. The cores are found to be significantly larger than the Abrikosov vortex cores in Nb, which is related to the effective coherence length in the proximity region (see Fig.1). We develop a theoretical approach that provides a fully self-consistent picture of the evolution of the vortex with the distance from Cu/Nb interface, the interface impedance, applied magnetic field, and temperature. This work opens a way for tuning of the superconducting properties of quantum hybrids.