Speaker
Bart Ludbrook
(Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada)
Description
B. M. Ludbrook, Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
C. N. Veenstra, Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
G. Levy, Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
N. D. Zhigadlo, Laboratory for Solid State Physics, ETH Zurich, Switzerland
A. Damascelli, Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
We present high-quality angle-resolved photoemission measurements on the superconductor MgB2. The renormalization of the sigma bands due to the electron-phonon coupling is clearly visible for the first time. Using a self-consistent fitting procedure we determine the self-energy, extract the bosonic 'glue', and calculate the momentum-dependent coupling parameter. The large values of \lambda~1.6 measured at specific momenta in the Brillouin zone are in agreement with ab-initio theoretical estimates. Comparison of these values with the Fermi surface average value of \lambda~0.7 is a direct demonstration of the strong electron-phonon coupling anisotropy, thought to be the origin of the large Tc in this material.
Primary author
Bart Ludbrook
(Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada)
