NSF National Extreme Ultrafast Science Facility (NeXUS)
At the heart of NeXUS is an ultrafast laser that delivers a kilowatt of power, the ability to control matter at the scale of individual electrons and atoms in systems that are far from equilibrium. This laser will be used to produce Extreme Ultraviolet (XUV) and soft X-ray pulses by high harmonic generation. These ultrafast pulses of XUV light will enable researchers to study how electrons move in molecules and materials at time scales as fast as attoseconds and length scales as small as angstroms.
Specifically, we plan to utilize time-resolved micron-scale angle-resolved photoemission spectroscopy (tr-microARPES) endstation to directly probe dynamic processes, including electron and spin relaxation, the evolution of spin-momentum locked states and the dynamics of correlated states.
In addition, we plan to use time-resolved X-ray magnetic circular dichroism (tr-XMCD) endstation to capture element-specific magnetization dynamics. The attosecond pulse duration at NeXUS provides to-date the fastest time dynamics among all existing facilities in the world. Therefore, the speed of spintronic, magnetic, and photonic degrees of freedom for information storage and transfer will be revealed at unparallel time resolution. In addition, the high repetition rate at NeXUS enables fast data acquisition with high dynamic reserve. This will allow studies of exotic magnetic systems with small magnetic moments such as 2D magnets, Moiré magnetism, and Kagome antiferromagnets.
A snapshot of NSF NeXUS Facility at Ohio State (image from link).
Types of measurements NeXUS system support:
Please feel free to contact Prof. Kelly Luo (at kelly.y.luo@usc.edu) and the NeXUS team (at nsf_nexus@osu.edu) if you are interested in working with us, be it as a student, a postdoctoral researcher, or as a collaborator.
MAgnetic X-raY Microscope with UHV Spectroscopy (MAXYMUS)
We plan to make use of the X-ray source from BESSYII synchrotron at Helmholtz Zentrum Berlin, Max Planck Institute. Specifically, the femtoslicing source at BESSYII allows optimal conditions for on-chip time-resolved scanning-transmission X-ray miscroscopy (tr-STXM). We plan to study spin-torque driven magnetic domain switching process on various magnetic and topological heterostructures.
References: [1] Birch, M.T., Powalla, L et al., Nat Commun 13, 3035 (2022) [2] Zhou, et al. ACS Appl. Electron. Mater. 4, 7, 3190–3197 (2022).