Spin-current amplification by stimulated spin pumping
arXiv:2109.02078 · doi:10.1103/PhysRevResearch.4.L042014
Abstract
Stimulated emission is a process during which an atomic system gives away energy to create a coherent photon. It is fundamental to the operation of the optical amplifier. Here we propose two mechanisms for amplifying AC spin currents in a solid-state magnetic medium by a stimulated spin pumping process. The first is synchronous and consists of phase-locked pulses that perturb a precessing magnetic moment. The second is asynchronous and is driven by DC spin currents. The amplification relies on a non-adiabatic interaction taking place in a ferromagnetic medium in which the magnetic moment emits spin angular momentum in the form of spin current before equilibrating with the environment. The pumped spin current amplifies or absorbs the injected AC spin current mimicking the operation of the optical gain medium as readily seen from the gain saturation profiles. The mechanisms we propose are a first step towards a realistic spin current amplifier.
17 pages, 4 figures
References in corpus (9)
- Experimental Investigation of Temperature-Dependent Gilbert Damping in Permalloy Thin Films
- FMR-related phenomena in spintronic devices
- Parallel pumping for magnon spintronics: Amplification and manipulation of magnon spin currents on the micron-scale
- Bridging magnonics and spin-orbitronics
- Topological magnon amplification
- Spin wave amplification using the spin Hall effect in permalloy/platinum bilayers
- Coherent control in a semiconductor optical amplifier operating at room temperature
- Microwave and spin transfer torque driven coherent control in ferromagnets
- Spin-torque switching and control using chirped oscillating currents