Associate Staff Scientists
Dr. Patrick Kirchmann
The emergence of order in complex quantum materials is governed by competing interactions of charge, lattice and spin degrees of freedom, which, however, often are difficult to disentangle in thermal equilbrium. Thus I am interested in applying non-equilbrium femtosecond pump-probe schemes and in particular time-resolved ARPES and time-resolved soft x-ray diffraction to such materials as CDW-BCS cross-over compounds, novel superconductors and topological insulators. These methods offer new insights to the underlying fundamental scattering processes and may open novel possibilities for device application.
Dr. Wei-Sheng Lee
I am interested in learning the underlying physics of strongly correlated materials through spectroscopic tools, which normally reveal lots of microscopic information of the electronic states. As an extension of my Ph. D. thesis work, I continue to explore the physics of high-Tc cuprates using the ultra-high resolution angle-resolved photoemission spectroscopy. The much improved resolution not only could lead to new discoveries, but also make possible a more quantitative analysis of the ARPES data. The other very exciting project I am working on is to explore the possibility of using the LCLS to do optical pump and X-ray probe experiments. New insight could be revealed via studying how the electronic state relaxes from an excited state back to the ground state.