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F. Weber, S. Rosenkranz, L. Pintschovius, J. Castellan, R. Osborn, W. Reichardt, R. Heid, K. Bohnen, E. Goremychkin, A. Kreyssig, K. Hradil, D. Albernathy:
"Electron-phonon coupling in the conventional superconductor YNi2B2C up to very high phonon energies studied by time-of-flight neutron spectroscopy";
Physical Review Letters, 109 (2012), 5; 057001-1 - 057001-5.

We report an inelastic neutron scattering investigation of phonons with energies up to 159 meV in the conventional superconductor YNi2B2C. Using the sweep mode, a newly developed time-of-flight technique involving the continuous rotation of a single crystal specimen, allowed us to measure a four-dimensional volume in (Q, E) space and, thus, determine the dispersion surface and linewidths of the A1g (≈102  meV) and Au (≈159  meV) type phonon modes over the whole Brillouin zone. Despite of having linewidths of Γ=10  meV, A1g modes do not strongly contribute to the total electron-phonon coupling constant λ. However, experimental linewidths show a remarkable agreement with ab initio calculations over the complete phonon energy range, demonstrating the accuracy of such calculations in a rare comparison to a comprehensive experimental data set.

Electron-phonon coupling; time-of-flight spectroscopy;superconductor

http://dx.doi.org/10.1103/PhysRevLett.109.057001