https://doi.org/10.1140/epjb/e2004-00273-y
On the use of STM superconducting tips at very low temperatures
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
Corresponding author: a sebastian.vieira@uam.es
Received:
17
February
2004
Revised:
12
May
2004
Published online:
7
September
2004
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 
cryostat. Spectra obtained with
superconducting tip and sample of Al show that the spectroscopic resolution
of our set-up is of 15 μeV. 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.
PACS: 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
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004