Reveal nature's secrets via peaking at the right space and time

Ultrafast materials science -- We are interested in ultrafast processes in quantum materials and aim at exploring new ways to measure and control how atoms and electrons move. The main focus is to understand nonequilibrium heterogeneities, particularly, arising from the complex interactions of electrons, spins and lattices in complex oxides and 2D materials.

Probe locally -- The ultrafast dynamics of mesoscale objects play pivotal roles in nonequilibrium material properties. Novel phenomena can arise from unique boundary conditions, collective dynamics, and mesoscale effects, which are typically washed out in ensemble averaged measurements. Probing at the appropriate space and time scales (ns to um, fs to us, see below) not only help understanding the fundamental physics but also inspires new energy and information applications on ultrafast time scales.

Probe directly -- Direct characterizations of selected degrees of freedom need a set of dedicated tools. We develop and use ultrafast probes at Argonne and large-scale facilities world wide, including ultrafast optical and THz spectroscopy in the Ultrafast Materials Science Lab (UMSL) at MSD, ultrafast laser facilities and electron microscope at Center of Nanoscale Materials, time-resolved x-ray nanodiffraction facilities at the Advanced Photon Source, as well as free-electron lasers around the world. One of the priorities in the technique development is to use coherent x-ray properties for advancing ultrafast x-ray diffraction with the unprecedented space and time resolution.

Some of examples of our recent research are shown below:

Our research is supported by Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Significant contributions are made by postdoctoral researchers and students below: Dr. Marc Zajac, Dr. Faran Zhou, Dr. Travis Frazer (co-advised), Dr. Jiawei Zhang (Alumni, RIKEN, Japan), Dr. Vladimir Stoica (Alumni, PSU), Dr. Qian Li (Alumni, Tsinghua U.), Dr. Kankan Cong (Alumni, Veeco), Mr. Samuel Marks (Alumni, U of Wisc, Madison), Dr. Qi Zhang (Alumni, Nanjing University), Dr. I-Cheng Tung (Alumni, Intel), Dr. Yi Zhu (Alumni, KLA Tencor), Mr. Kiyan Tavangar (Alumni, U of Chicago).