Fabrication and characterization of scanning tunneling microscopy superconducting Nb tips having highly enhanced critical fields
arXiv:cond-mat/0412095 · doi:10.1016/j.physc.2004.12.001
Abstract
We report a simple method for the fabrication of Niobium superconducting (SC) tips for scanning tunnelling microscopy which allow atomic resolution. The tips, formed in-situ by the mechanical breaking of a niobium wire, reveal a clear SC gap of 1.5 meV and a critical temperature Tc=9.2+-0.3 K as deduced from Superconductor Insulator Normal metal (NIS) and Superconductor Insulator Superconductor (SIS) spectra. These match the values of bulk Nb samples. We systematically find an enhanced value of the critical magnetic field in which superconductivity in the tip is destroyed (around 1 T for some tips) up to five times larger than the critical field of bulk Nb (0.21 T). Such enhancement is attributed to a size effect at the tip apex
arXiv commentto appear in Physica C
References in corpus (5)
- Two Gap State Density in MgB: A True Bulk Property or A Proximity Effect?
- Josephson scanning tunneling microscopy
- Strong enhancement of superconductivity in a nanosized Pb bridge
- The fabrication of reproducible superconducting scanning tunneling microscope tips
- Superconducting nanobridges under magnetic fields
Cited by in corpus (7)
- Probing the superfluid velocity with a superconducting tip: the Doppler shift effect
- Microwave photon-assisted phase-incoherent Cooper-pair tunneling in a Josephson STM
- Probing the superconducting condensate on a nanometer scale
- Plasma etching of superconducting Niobium tips for scanning tunneling microscopy
- dc Josephson Effect in Metallic Single-Walled Carbon Nanotubes
- The feedback driven atomic scale Josephson microscope
- Enhancing sensitivity in atomic force microscopy for planar tip-on-chip probes