Field-assisted sub-terahertz spin pumping and auto-oscillation in NiO
Abstract
Spin pumping converting sub-terahertz electromagnetic waves to DC spin currents has recently been demonstrated in antiferromagnets (AFMs) with easy-axis magnetic anisotropy. However, easy-plane AFMs such as NiO, which are easier to prepare experimentally, are considered to be bad candidates for spin pumping because the Néel vector oscillation is linearly polarized, placing a major restriction on the material choice for practical applications. Through a case study of NiO, we show that an applied magnetic field below the spin–flop transition can substantially modify the polarization of the resonance eigenmodes, which enables coherent sub-terahertz spin pumping as strong as that in easy-axis AFMs. In addition, we find that an applied magnetic field can significantly reduce the threshold of Néel vector auto-oscillation triggered by spin-transfer torques. These prominent field-assisted effects can greatly facilitate spintronic device engineering in the sub-terahertz frequency regime.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 15, 2022
- Source ID
- 10.1063/5.0097211
Entities
People
- Mingda Guo
- Ran Cheng
Organizations
- Air Force Office of Scientific Research
- University of California