The work on excitons, originating from ultrathin materials, could impact future electronics and establishes a new way to study these particles through a powerful instrument at the Brookhaven National Laboratory. Schematic showing how exotic particles known as excitons can “hop” between nickel atoms (grey dots) in nickel dihalide materials. The excitons are represented by the red and light-blue orbitals. Credits: Image courtesy of the Comin Laboratory.
Editor’s note: The following article was originally issued by the Massachusetts Institute of Technology (MIT). Jonathan Pelliciari and Valentina Bisogni, beamline scientists at the Soft Inelastic X-ray Scattering (SIX) beamline at the at the National Synchrotron Light Source II (NSLS-II), a U.S. Department of Energy (DOE) Office of Science User Facility at DOE’s Brookhaven National Laboratory, collaborated with researchers from several institutions in this MIT led research into the nature of excitons in magnetic two-dimensional materials. Using resonant inelastic X-ray scattering (RIXS), a technique that can only be performed in a few facilities around the world, the team was able to see the microscopic origin of excitons in nickel dihalide, providing insight into the role these particles play in magnetism. Understanding these mechanisms could lead to new nickel-based materials that can be tuned for specific electronic and magnetic properties that could be beneficial in quantum computing applications. MIT is a partner institution of the Co-design Center for Quantum Advantage (C2QA), a National Quantum Information Science Research Center funded by the DOE Office of Science. Brookhaven Lab is the lead institution for C2QA. For more information on Brookhaven’s role in this research, contact Denise Yazak (dyazak@bnl.gov, 631-344-6371).
MIT physicists and colleagues report new insights into exotic particles key to a form of magnetism that has attracted growing interest because it originates from ultrathin materials only a few atomic layers thick. The work, which could impact future electronics and more, also establishes a new way to study these particles through a powerful instrument at the National Synchrotron Light Source II at Brookhaven National Laboratory.
Among their discoveries, the team has identified the microscopic origin of these particles, known as excitons. They showed how they can be controlled by chemically “tuning” the material, which is primarily composed of nickel. Further, they found that the excitons propagate throughout the bulk material instead of being bound to the nickel atoms.
Finally, they proved that the mechanism behind these discoveries is ubiquitous to similar nickel-based materials, opening the door for identifying — and controlling — new materials with special electronic and magnetic properties.
The open-access results are reported in the July 12 issue of Physical Review X.
“We’ve essentially developed a new research direction into the study of these magnetic two-dimensional materials that very much relies on an advanced spectroscopic method, resonant inelastic X-ray scattering (RIXS), which is available at Brookhaven National Lab,” says Riccardo Comin, MIT’s Class of 1947 Career Development Associate Professor of Physics and leader of the work. Comin is also affiliated with the Materials Research Laboratory and the Research Laboratory of Electronics.
Comin’s colleagues on the work include Connor A. Occhialini, an MIT graduate student in physics, and Yi Tseng, a recent MIT postdoc now at Deutsches Elektronen-Synchrotron (DESY). The two are co-first authors of the Physical Review X paper.
Additional authors are Hebatalla Elnaggar of the Sorbonne; Qian Song, a graduate student in MIT’s Department of Physics; Mark Blei and Seth Ariel Tongay of Arizona State University; Frank M. F. de Groot of Utrecht University; and Valentina Bisogni and Jonathan Pelliciari of Brookhaven National Laboratory.
Read more on BNL website
Image: Schematic showing how exotic particles known as excitons can “hop” between nickel atoms (grey dots) in nickel dihalide materials. The excitons are represented by the red and light-blue orbitals.
Credit: Image courtesy of the Comin Laboratory.