Magnetic resonance imaging of spin-wave transport and interference in a magnetic insulator

Image credit: [Tao Yu]

Abstract

Spin waves—the elementary excitations of magnetic materials—are prime candidate signal carriers for low-dissipation information processing. Being able to image coherent spin-wave transport is crucial for developing interference-based spin-wave devices. We introduce magnetic resonance imaging of the microwave magnetic stray fields that are generated by spin waves as a new approach for imaging coherent spin-wave transport. We realize this approach using a dense layer of electronic sensor spins in a diamond chip, which combines the ability to detect small magnetic fields with a sensitivity to their polarization. Focusing on a thin-film magnetic insulator, we quantify spin-wave amplitudes, visualize spin-wave dispersion and interference, and demonstrate time-domain measurements of spin-wave packets. We theoretically explain the observed anisotropic spin-wave patterns in terms of chiral spin-wave excitation and stray-field coupling to the sensor spins. Our results pave the way for probing spin waves in atomically thin magnets, even when embedded between opaque materials.

Publication
Sci. Adv. 6, eabd3556 (2020)

Supplementary notes can be added here, including code and math.

Tao Yu
Tao Yu
Professor, Group Leader

My research interests include Magnetism, Spintronics, Unconventional superconductivity, Quantum transport in low dimensional electronics, and Strong light-matter interaction.

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