Hypergiant spin polarons photogenerated in ferromagnetic europium chalcogenides
Abstract
We find that in the ferromagnetic semiconductor EuS, near its Curie temperature, a single band edge photon generates a spin polaron (SP), whose magnetic moment approaches 20 000 Bohr magnetons. This is much larger than the supergiant photoinduced SPs in antiferromagnetic europium chalcogenides, reported previously. The larger SP in ferromagnetic EuS, and still larger expected for EuO, is explained by a larger Bohr radius of the photoexcited electron state, which encircles and polarizes a greater number of lattice spins. However, because the wave function of the photoexcited electron spreads over a greater volume, the photoexcited electron's exchange interaction with individual lattice spins weakens, which makes the SP more easily quenched thermally.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 13, 2020
- Source ID
- 10.1063/1.5143311
Entities
People
- Andre B. Henriques
- Jagadeesh Moodera
- P. H. O. Rappl
- X. Gratens
- Yunbo Ou
Organizations
- Massachusetts Institute of Technology
- National Council for Scientific and Technological Development
- National Science Foundation
- Office of Naval Research
- São Paulo Research Foundation
- University of São Paulo