Tabletop system performs angle-resolved photoemission spectroscopy

Researchers in the laboratory of Daniel Dessau in the department of physics and JILA at the University of Colorado (Boulder) have developed a tabletop system to perform angle-resolved photoemission spectroscopy (ARPES).

Feb 1st, 2006

Researchers in the laboratory of Daniel Dessau in the department of physics and JILA at the University of Colorado (Boulder) have developed a tabletop system to perform angle-resolved photoemission spectroscopy (ARPES). This technique is one of the key tools used in the quest to understand the complex electronic interactions responsible for high temperature superconductivity. Typically, ARPES experiments are performed at large multiuser synchrotron light sources costing on the order of a $100 million. Instead, the Dessau lab system uses 6-eV photons from the fourth harmonic of a Ti:sapphire laser produced through two stages of nonlinear second-harmonic generation in BBO (beta barium borate) crystals.

The resulting flux of 2 × 1014 photons/s in a bandwidth of less than 5 meV represents about two orders of magnitude improvement over even the best synchrotron beam lines. The relatively low photon energy also greatly increases the momentum resolution and decreases the background signal of ARPES relative to higher-energy synchrotrons. In addition, the pulsed nature of the Ti:sapphire laser opens up the possibility to directly observe electron dynamics using ARPES. Contact Jacob Koralek at Koralek@colorado.edu.

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