ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
We report on the study of the interband pairing interaction in the two-bandsuperconductor MgB2 by tunneling spectroscopy using thin film tunnel junctions. The filmswere deposited in situ by an approach comprising a conventional planar B sputter gun and aspecial homemade Mg evaporator providing a high vapor pressure. For the tunnelingexperiments sandwich-type crossed-strip tunnel junctions with a native MgB2 oxide as thepotential barrier and Al, In or Pb counterelectrodes were prepared. Voltage-dependentdifferential conductance measurements revealed estimates of the barrier thickness and heightof 1.5 nm and 1.6 eV, respectively, and allowed us to determine the phonon-inducedstructures in the tunneling density of states of the phonon-mediated superconductor MgB2.The analysis of the reduced density of states using the standard single-band Eliashbergequations yielded an effective electron-phonon spectral function accounting for the smallerenergy gap. A further analysis involving ab-initio LDA calculations and the two-bandEliashberg equations revealed that the dominant feature in the effective spectral function, astrong peak at 58 meV, was mainly due to the interband pairing interaction
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.47.69.pdf
