Coherent X-Ray Study of Fluctuations during Domain Coarsening

Beyond simple exponential correlation functions and equilibrium dynamics in x-ray photon correlation spectroscopy

“…This two-time approach was pioneered for XPCS by Sutton and co-workers [53,54] in a series of experiments on materials with non-stationary dynamics, such as alloys undergoing phase separation. In particular, this work demonstrated how plotting the instantaneous correlations provides an effective method for identifying and characterizing rapidly evolving dynamics, for example enabling tests of critical scaling [53]- [56].…”

Non-Markovianity measure using two-time correlation functions

“…In particular, two-time correlation functions are experimentally measurable. For examples, the two-time correlation functions of the electromagnetic field emitted by an atom can be measured through fluorescence spectrum [1][2][3][4]; the two-time correlation functions of the number of emitted photons give the information about the photon statistics and describe the behavior of photon bunching and antibunching [1][2][3][4]; two-time correlation functions have also been measured in optical measurements and light-harvesting photosynthesis for testing the non-Markovian memory effects [33,34]; the two-time correlation functions of the electric current through nanostructure devices are used in quantum transport to study the current fluctuations and noise spectrum [35][36][37]. Intuitively, two-time correlation functions correlating a past event with its future provide useful information about the system-environment backaction processes revealing the non-Markovian memory effects.…”

Contribution of synchrotron radiation to small-angle X-ray scattering studies in hard condensed matter

“…In the case of non-equilibrium phenomena, discussed hereafter, a two-time correlation function is needed: the phase separation during the coarsening regime is a generic non-equilibrium phenomenon of non-conservative phase transitions. Several isothermal kinetics have been studied on a sodium borosilicate glass (Malik et al, 1998), and on Al-Li , Al-Zn and AlAg alloys (Stadler et al, 2004).…”