PT Journal AU Peltonen, JT Astafiev, OV Korneeva, YP Voronov, BM Korneev, AA Charaev, IM Semenov, AV Golt'sman, GN Ioffe, LB Klapwijk, TM Tsai, JS TI Coherent flux tunneling through NbN nanowires SO Phys. Rev. B JI Phys. Rev. B PY 2013 BP 220506 (1 to 5) VL 88 IS 22 DI 10.1103/PhysRevB.88.220506 DE NbN nanowires AB We demonstrate evidence of coherent magnetic flux tunneling through superconducting nanowires patterned in a thin highly disordered NbN film. The phenomenon is revealed as a superposition of flux states in a fully metallic superconducting loop with the nanowire acting as an effective tunnel barrier for the magnetic flux, and reproducibly observed in different wires. The flux superposition achieved in the fully metallic NbN rings proves the universality of the phenomenon previously reported for InOx. We perform microwave spectroscopy and study the tunneling amplitude as a function of the wire width, compare the experimental results with theories, and estimate the parameters for existing theoretical models. ER