Excitons, microscopic particle-like objects, have recently gained attention due to their potential applications in developing new technologies based on magnetism. Researchers at the U.S. Department of Energy’s Brookhaven National Laboratory conducted a study to explore the formation and behavior of excitons in a class of materials known as van der Waals magnets, focusing on nickel phosphorus trisulfide (NiPS3). The findings of this study, published in the journal Nature Communications, shed light on the complex relationship between optical and magnetic properties in these materials.
The research group utilized the National Synchrotron Light Source II (NSLS-II) to study the crystalline material NiPS3. By employing a technique called resonant inelastic X-ray scattering (RIXS) at the Soft Inelastic X-ray Scattering (SIX) beamline, the scientists were able to examine the electronic properties of the material with high resolution. This cutting-edge experimental station allowed them to uncover details about the exciton structure and motion in NiPS3, addressing a challenge that had previously eluded researchers.
Through their investigations, the team discovered that exciton formation and propagation in NiPS3 are influenced by the Hund’s exchange interaction, a physics principle governing the energy of electron spin configurations. This exchange interaction provides the energy needed for excitons to form in the material. Additionally, the researchers observed that excitons disperse through the crystal in a manner similar to a double-magnon spin disturbance, revealing the intricate relationship between excitons and magnons in van der Waals magnets.
Looking ahead, the researchers anticipate that advancements in instrumentation and techniques such as RIXS and electron microscopy will enable even more precise measurements of NiPS3 and other van der Waals magnets. By continuing to explore the interaction between excitons and magnetism in these materials, the scientific community may uncover new possibilities for leveraging these phenomena in future technologies.
The study conducted at Brookhaven National Laboratory provides valuable insights into the behavior of excitons in van der Waals magnets, particularly in NiPS3. By utilizing advanced experimental techniques and analytical methods, the researchers have contributed to our understanding of the intricate relationship between optical and magnetic properties in these materials. With further research and technological developments, the potential applications of excitons in magnetism-based technologies may become even more promising.