Spin Transport in Thick Insulating Antiferromagnetic Films

Abstract

Spin transport of magnonic excitations in uniaxial insulating antiferromagnets (AFs) is investigated. In linear response to spin biasing and a temperature gradient, the spin transport properties of normal-metal--insulating antiferromagnet--normal-metal heterostructures are calculated. We focus on the thick-film regime, where the AF is thicker than the magnon equilibration length. This regime allows the use of a drift-diffusion approach, which is opposed to the thin-film limit considered by Bender {\it et al.} 2017, where a stochastic approach is justified. We obtain the temperature- and thickness-dependence of the structural spin Seebeck coefficient $\mathcal{S}$ and magnon conductance $\mathcal{G}$. In their evaluation we incorporate effects from field- and temperature-dependent spin conserving inter-magnon scattering processes. Furthermore, the interfacial spin transport is studied by evaluating the contact magnon conductances in a microscopic model that accounts for the sub-lattice symmetry breaking at the interface. We find that while inter-magnon scattering does slightly suppress the spin Seebeck effect, transport is generally unaffected, with the relevant spin decay length being determined by non-magnon-conserving processes such as Gilbert damping. In addition, we find that while the structural spin conductance may be enhanced near the spin flip transition, it does not diverge due to spin impedance at the normal metal|magnet interfaces.

arXiv comment14 pages and 6 figures

References in corpus (27)

• Antiferromagnetic spintronics
• Antiferromagnetic spintronics
• Electrical switching of an antiferromagnet
• Electrically controlled long-distance spin transport through an antiferromagnetic insulator
• Relativistic Neel-order fields induced by electrical current in antiferromagnets
• Writing and Reading antiferromagnetic Mn${}_2$Au: Néel spin-orbit torques and large anisotropic magnetoresistance
• Spin pumping and spin-transfer torques in antiferromagnets
• Antiferromagnonic Spin Transport from Y${}_3$Fe${}_5$O${}_{12}$ into NiO
• Antiferromagnetic spin Seebeck Effect
• Magnon spin transport driven by the magnon chemical potential in a magnetic insulator
• Enhancement of Thermally Injected Spin Current through an Antiferromagnetic Insulator
• Thermal generation of spin current in an antiferromagnet
• Superfluid spin transport through antiferromagnetic insulators
• Magnon transport in quasi-two-dimensional van der Waals antiferromagnets
• Experimental Signatures of Spin Superfluid Ground State in Canted Antiferromagnet Cr2O3 via Nonlocal Spin Transport
• Spin colossal magnetoresistance in an antiferromagnetic insulator
• Spin Seebeck effect in antiferromagnets and compensated ferrimagnets
• Spin Seebeck effect through antiferromagnetic NiO
• Interfacial Spin and Heat Transfer between Metals and Magnetic Insulators
• Spin Superfluidity in Biaxial Antiferromagnetic Insulators
• Enhanced Spin Conductance of a Thin-Film Insulating Antiferromagnet
• Spin Seebeck effect in a polar antiferromagnet $\alpha$-Cu${}_2$V${}_2$O${}_7$
• Electrically Driven Bose-Einstein Condensation of Magnons in Antiferromagnets
• Interfacial Spin Seebeck effect in noncollinear magnetic systems
• Chemical potential of an antiferromagnetic magnon gas
• Theory of spin transport through antiferromagnetic insulator
• Intrinsic Spin Decay Length in Antiferromagnetic Insulator

Cited by in corpus (18)

• Observation of Antiferromagnetic Magnon Pseudospin Dynamics and the Hanle effect
• Spin Seebeck Effect near the Antiferromagnetic Spin-Flop Transition
• Antiferromagnetic magnon pseudospin: Dynamics and diffusive transport
• Non-local spin Seebeck effect in the bulk easy-plane antiferromagnet NiO
• All-electrical Magnon Transport Experiments in Magnetically Ordered Insulators
• Local and nonlocal spin Seebeck effect in lateral Pt-$\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_3$-Pt devices at low temperatures
• Antiferromagnetic spin Seebeck effect across the spin-flop transition: A stochastic Ginzburg-Landau simulation
• Cross-sublattice Spin Pumping and Magnon Level Attraction in van der Waals Antiferromagnets
• An insulating doped antiferromagnet with low magnetic symmetry as a room temperature spin conduit
• Theory of the low-temperature longitudinal spin Seebeck effect
• Thermal squeezing and nonlinear spectral shift of magnons in antiferromagnetic insulators
• Magnon spin transport around the compensation magnetic field in easy-plane antiferromagnetic insulators
• Chiral magnon-polaron edge states in Heisenberg-Kitaev magnets
• Magnonic Thermal Machines
• Ginzburg-Landau theory of spin pumping through an antiferromagnetic layer near the Néel temperature
• Surface acoustic wave driven acoustic spin splitter in d-wave altermagnetic thin films
• Theory of magnon hydrodynamics in collinear antiferromagnets
• Spin Nernst Effect of Antiferromagnetic Magnons in the Presence of Spin Diffusion