Detection of Domain Dynamics by High Energy Photons: Proposals in One-Dimensional Photoinduced Phase Transition Systems

We propose the detection of domain dynamics in a one-dimensional system by using high energy photons such as synchrotron radiation. The domain here means that of a different phase formed in the background of an original phase. Using high energy photons, it is expected that not only k=0 states with k being the momentum of its center of gravity motion, but also finite k states are possible to be detected. We theoretically demonstrate how they are observed, with nonresonant inelastic x-ray scattering and valence photoemission as concrete examples. In the former, we mainly detect charge excitations, particularly, the center of gravity and the spatial size of the domain as its basic two degrees of freedom, while, in the latter, spin excitations inside the domain also play an essential role.