Opportunity at National Institute of Standards and Technology NIST
Spin-orbit Phenomena in Magnetic Structures for Spintronics and Spin-orbitronics
Physical Measurement Laboratory, Quantum Electromagnetics Division
Please note: This Agency only participates in the February and August reviews.
|Justin M Shaw
We are measuring the dynamic properties of continuous magnetic thin films and nano-patterned magnetic structures to study various phenomena that result from the spin-orbit interaction. In magnetic systems, the spin-orbit interaction is responsible for phenomena such as damping, anisotropy, interfacial spin-obit torques (such as the spin-Hall effect) and the Dzyaloshinskii-Moriya interaction (DMI). As part of this effort, we have developed several novel microwave and optical measurement capabilities that allow us to quantify the strength of these interactions. These capabilities include broadband ferromagnetic resonance (FMR) spectroscopy, Brillouin light scattering (BLS) spectroscopy, ultra-fast high-harmonic generation (HHG) extreme ultraviolet spectroscopy/microscopy, and heterodyne magneto-optical microwave microscopy (H-MOMM). The H-MOMM system is a one-of-its-kind capability that allows us to measure the spin-wave eigenmodes and damping in nanomagnets and nanodevices down to 50 nm in size with potential to measure even smaller structures. Studying such structures has revealed new phenomena such as mode-dependent damping. In addition to eigenmodes, we are studying other magnetic textures such as skyrmions in nanomagnets that can exist in either a dynamic or static state. For this, careful evaluation and engineering of the DMI, exchange interaction, anisotropy and saturation magnetization as well as magnetic imaging is essential. In addition, we are also interested in understanding the strength and direction of spin-orbit torques at interfaces between ferromagnets and non-magnetic materials and how it related to properties such as the spin-diffusion length, spin-memory loss and spin-mixing conductance. We are able to study both dc and high-frequency SOTs in fabricated devices as well as in continuous films. Sample are fabricated with our multiple and dedicated sputtering chambers as well as a fully equipped cleanroom that includes a state-of-the-art e-beam lithography tool. Material characterization is performed with x-ray diffraction, electron microscopy, various magnetometers, FMR and atomic force microscopy.
Spintronics; Spin-orbitronics; Skyrmions; Spin-dynamics; Magneto-optics; Ferromagnetic resonance; High-harmonic generation
Open to U.S. citizens
Open to Postdoctoral applicants