Anomalous magnetoresistance oscillations and enhanced superconductivity in single-crystal Pb nanobelts

Using atomically flat single-crystal Pb ultrathin films grown on Si(111) substrate by molecular beam epitaxy, we fabricated Pb nanobelts of 28 atomic monolayers thick, 285nm wide, and 10μm long by focus ion beam technique. The transport property is measured and the results are compared to the Pb films. We find that below the superconducting transition temperature TC, the resistance of the nanobelts exhibits clear and reproducible oscillations as a function of perpendicular magnetic field, which are not observed in the Pb films. In addition, TC enhancement was also observed in the nanobelts. The results suggest that the single-crystal Pb nanobelts prepared on Si semiconductor substrate offer a great opportunity for integrating superconducting circuits in a single Si chip.