Photoelectron spectroscopy of the laser-excited bar X surface state on GaAs(110) using synchrotron radiation

An excited surface state on GaAs(110) has been investigated using a technique which populates the state with a laser pulse and measures its properties by time-resolved photoelectron spectroscopy using synchrotron radiation. Measurements of momentum, energy, and lifetime show that this is an intrinsic surface state near bar X in the surface Brillouin zone which equilibrates with bulk conduction electrons during the 5-ns pump pulse. The narrow photoelectron band increases linearly in kinetic energy with the probe photon energy, and no final-state effects appear in the limited energy range investigated