Quasiparticle dynamics of Bi₂Sr₂CaCu₂O₈
from high momentum resolution laser-based ARPES

Daniel Dessau

Dept of Physics, University of Colorado, 2000 Colorado Ave, Boulder, USA

We present the first laser based angle resolved photoemission (ARPES) study of the High Tc superconductor Bi2Sr2CaCu2O8. This new technique uses 6 eV photons from the 4th harmonic of a high repetition rate Ti:sapphire oscillator. The new light source offers increased count rate and momentum resolution, while reducing surface sensitivity and background relative to traditional ARPES light sources. In addition to reproducing BSCCO features seen in previous ARPES experiments (d-wave superconducting gap, dispersion kinks, etc.) these improvements have allowed us to make much stronger statements about the nature of the quasiparticle dynamics both in the normal and superconducting states.