Frequency-dependent Phonon-mediated Unidirectional Magnetoresistance in a Metal on an Insulator with Highly Nonequilibrium Magnons

Abstract

Heavy metal (HM)/magnet bilayers host many magnetoresistances (MR) and spin caloritronic effects. Here we show that the spin Peltier effect and electron-phonon scattering produce much larger unidirectional MR of an HM on a magnetic insulator than existing theories that neglect the interplay between MR and spin caloritronic effects. By accounting for local nonequilibrium in both the magnon chemical potential and temperature, our analytical model attributes the observed frequency dependence of the spin Peltier MR and the spin Seebeck effect to the reduction of the thermal penetration depth, which approaches the 1 micron scale magnon spin diffusion length at high frequencies.

SES and HL contributed equally. Main paper: 13 pages, 4 figures; supplemental: 44 pages, 16 figures

References in corpus (8)

• Dissipationless Quantum Spin Current at Room Temperature
• Theory of magnon-driven spin Seebeck effect
• Thermal imaging of spin Peltier effect
• Magnetoresistance due to edge spin accumulation
• Quantitative Temperature Dependence of Longitudinal Spin Seebeck Effect at High Temperatures
• Theory of unidirectional spin Hall magnetoresistance in heavy-metal/ferromagnetic-metal bilayers
• Giant magnon spin conductivity approaching the two-dimensional transport regime in ultrathin yttrium iron garnet films
• Magnetic-field-induced suppression of spin Peltier effect in Pt/${\mathrm{Y}}_3\mathrm{F}{\mathrm{e}}_5{\mathrm{O}}_{12}$ system at room temperature

Cited by in corpus (2)

• Theory of nonlinear magnetoelectric transport effects in normal-metal $-$ magnetic-insulator heterostructures
• Magnon-mediated electric current drag and nonlocal spin-Peltier effect in the ac regime