| Affiliation: | (1) Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain |
| Abstract: | We report on high quality local tunnel spectroscopy measurements in superconductors using in-situ fabricated superconducting tips as counterelectrode. The experiments were made at very low temperatures using a dilution refrigerator and a 3He cryostat. Spectra obtained with superconducting tip and sample of Al show that the spectroscopic resolution of our set-up is of 15  eV. Following the observation of Josephson current in tunnelling regime (with tips of Pb and of Al), we discuss the feasibility of Scanning Josephson Spectroscopy with atomic size resolution. Experiments showing new applications of these superconducting tips under applied external magnetic fields are also reported.Received: 12 May 2004, Published online: 7 September 2004PACS: 73.63.Rt Nanoscale contacts - 74.25.Fy Transport properties (electric and thermal conductivity, thermoelectric effects, etc.) - 74.25.Ha Magnetic properties - 74.50. + r Tunnelling phenomena; point contacts, weak links, Josephson effects - 74.78.Na Mesoscopic and nanoscale systems - 74.80.Fp Point contacts; SN and SNS junctions |
