A generalized model of magnon kinetics and subgap magnetic noise

Abstract

Magnetic noise spectroscopy provides a noninvasive probe of spin dynamics in magnetic materials. We consider two-dimensional magnetically ordered insulators with magnon excitations, especially those supporting long-distance magnon transport, where nitrogen-vacancy (NV) centers enable the access to (nearly) ballistic transport regime of magnons. We develop a generalized theory to describe the magnon transport across a wide range of length scales. The longitudinal dynamic spin susceptibility is derived from the Boltzmann equation and extended to a Lindhard form, which is modified by both the spin-conserving magnon collisions and spin relaxation. Our result is consistent with the diffusive (ballistic) model for the length scale much larger (smaller) than the magnon mean free path, and provides a description for the intermediate regime. We also give a prediction for the NV transition rate in different magnon transport regimes.

revised version, 7 pages, 4 figures, including appendices

References in corpus (5)

• High-sensitivity diamond magnetometer with nanoscale resolution
• Bose-Einstein Condensation in Magnetic Insulators
• Magnon Mediated Electric Current Drag Across a Ferromagnetic Insulator Layer
• Nanoscale Detection of Magnon Excitations with Variable Wavevectors Through a Quantum Spin Sensor
• Quantum Sensing of Spin Transport Properties of an Antiferromagnetic Insulator

Cited by in corpus (6)

• Giant magnon spin conductivity approaching the two-dimensional transport regime in ultrathin yttrium iron garnet films
• Solid-state platform for cooperative quantum dynamics driven by correlated emission
• Flavors of Magnetic Noise in Quantum Materials
• Signatures of non-local conductivity in near-field microscopy
• Spin-qubit Noise Spectroscopy of Magnetic Berezinskii-Kosterlitz-Thouless Physics
• Quantum-impurity sensing of altermagnetic order