Related Experiment Video
Updated: Aug 1, 2026

Atom Probe Tomography Studies on the Cu(In,Ga)Se2 Grain Boundaries
Published on: April 22, 2013
Two-gap state density in MgB(2): a true bulk property or a proximity effect?
F Giubileo1, D Roditchev, W Sacks
1Physics Department and INFM Unit, University of Salerno, via S. Allende, 84081 Baronissi (SA), Italy.
Abstract:
We report on the temperature dependence of the quasiparticle density of states in the simple binary compound MgB(2) directly measured using scanning tunneling microscope (STM). To achieve high quality tunneling conditions, a small crystal of MgB(2) is used as a tip in the STM experiment. The "sample" is chosen to be a 2H- NbSe(2) single crystal presenting an atomically flat surface. At low temperature the tunneling conductance spectra show a gap at the Fermi energy followed by two well-pronounced conductance peaks on each side. They appear at voltages V(S) approximately +/-3.8 mV and V(L) approximately +/-7.8 mV. With rising temperature both peaks disappear at the T(C) of the bulk MgB(2), a behavior consistent with the model of two-gap superconductivity. The possibility of a particular proximity effect is also discussed.
More Related Videos
Related Concept Videos
Valence Bond Theory
Valence Bond Theory
Density
Atomic Nuclei: Nuclear Spin State Population Distribution
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
Bulk Density of Aggregate
Most natural mineral aggregates, like sand and gravel,...

