Time-resolved photoemission of a nonequilibrium charge-density-wave-ordered system

POSTER

Abstract

We examine the response of an electronic charge-density-wave-ordered (CDW) system in a time-resolved pump-probe photoemission spectroscopy experiment. In this experiment, the system is driven out of the equilibrium by a high intensity but low frequency pump pulse and then photoexcited by a low intensity but high frequency probe pulse. The system we examine is the half-filled Falicov-Kimball model, which has an exact solution within dynamical mean-field theory. This system has an interesting quantum critical point in the ordered phase, which is insulating at $T=0$, but is metallic for all $T>0$. Interestingly, the quantum critical CDW cannot be pumped easily --- whatever energy is pumped in during the leading edge of the pump pulse is pumped out on the trailing edge. When one is in the weakly correlated insulator or the strongly correlated insulator, the system is much more easily pumped. These features occur only within the ordered phase.

Authors

  • Oleg Matveev

    Department of Physics, Georgetown University, Washington, DC, Georgetown University

  • Andrij Shvaika

    Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, Lviv, Ukraine

  • Thomas Devereaux

    Stanford Unviersity, Stanford Institute for Materials and Energy Sciences, Stanford University & SLAC, SLAC National Accelerator Laboratory, SLAC National Accelerator Laboratory, Stanford Institute for Materials and Energy Sciences, Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, USA, Stanford Univ, SLAC National Accelerator Laboratory/Stanford University, Stanford Institute for Material and Energy Sciences

  • James Freericks

    Georgetown University, Department of Physics, Georgetown University, Washington, DC