Anisotropic Excitons Reveal Local Spin Chain Directions in a van der Waals Antiferromagnet
Abstract
A long‐standing pursuit in materials science is to identify suitable magnetic semiconductors for integrated information storage, processing, and transfer. Van der Waals magnets have brought forth new material candidates for this purpose. Recently, sharp exciton resonances in antiferromagnet NiPS3 have been reported to correlate with magnetic order, that is, the exciton photoluminescence intensity diminishes above the Néel temperature. Here, it is found that the polarization of maximal exciton emission rotates locally, revealing three possible spin chain directions. This discovery establishes a new understanding of the antiferromagnet order hidden in previous neutron scattering and optical experiments. Furthermore, defect‐bound states are suggested as an alternative exciton formation mechanism that has yet to be explored in NiPS3. The supporting evidence includes chemical analysis, excitation power, and thickness dependent photoluminescence and first‐principles calculations. This mechanism for exciton formation is also consistent with the presence of strong phonon side bands. This study shows that anisotropic exciton photoluminescence can be used to read out local spin chain directions in antiferromagnets and realize multi‐functional devices via spin‐photon transduction.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 23, 2023
- Source ID
- 10.1002/adma.202206585
Entities
People
- Chunhao Guo
- Dario Rocca
- David Lujan
- Di Huang
- Dong Seob Kim
- Edoardo Baldini
- Frank Y. Gao
- Jeongheon Choe
- Kejun Li
- Kung‐hsuan Lin
- Li Yang
- Raju Kalaivanan
- Raman Sankar
- Shang‐Fan Lee
- Shivani Sharma
- Ting‐hsuan Wu
- Xiaoqin Li
- Yuan Ping
Organizations
- Academia Sinica
- Air Force Research Laboratory
- Brookhaven National Laboratory
- National Science Foundation
- National Science and Technology Council
- Office of Basic Energy Sciences
- Robert A. Welch Foundation
- Tongji University
- University of California, Santa Cruz
- University of Lorraine
- University of Texas at Austin
- Washington University in St. Louis