Direct observation of a Fermi surface and superconducting gap in LuNi2B2C
Date
2008-04-01
Authors
Starowicz, P.
Liu, C.
Khasanov, R.
Kondo, Takeshi
Samolyuk, G. D.
Gardenghi, D.
Lee, Y.
Ohta, T.
Harmon, B. N.
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American Physical Society
Abstract
We measured the Fermi surface (FS), band dispersion, and superconducting gap in LuNi2B2C using angle resolved photoemission spectroscopy. Experimental data were compared to the tight-binding version of the linear muffin-tin orbital (LMTO) method and linearized augmented plane-wave (LAPW) calculations. We found reasonable agreement between the two calculations and experimental data. The measured FS exhibits large parallel regions with a nesting vector that agrees with a previous positron annihilation study and calculations of the generalized susceptibility. The measured dispersion curves also agree reasonably well with the TB-LMTO calculations, although with some differences in the strength of the hybridization. In addition, the spectrum in the superconducting state revealed a 2 meV superconducting gap. The data also clearly show the presence of a coherent peak above the chemical potential mu, which originates from thermally excited electrons above the energy of 2 Delta. This feature was not previously observed in the Lu-based material.
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Comments
This article is published as Starowicz, P., C. Liu, R. Khasanov, T. Kondo, G. Samolyuk, D. Gardenghi, Y. Lee et al. "Direct observation of a Fermi surface and superconducting gap in LuNi 2 B 2 C." Physical Review B 77, no. 13 (2008): 134520.
DOI: 10.1103/PhysRevB.77.134520.
Copyright 2008 American Physical Society.
Posted with permission.