Fully Spin-transparent magnetic interfaces enabled by insertion of a paramagnetic NiO layer

Abstract

Spin backflow and spin-memory loss have been well established to considerably lower the interfacial spin transmissivity of metallic magnetic interfaces and thus the energy efficiency of spin-orbit torque technologies. Here we report that spin backflow and spin-memory loss at Pt-based heavy metal/ferromagnet interfaces can be effectively eliminated by inserting an insulating paramagnetic NiO layer of optimum thickness. The latter enables the thermal magnon-mediated essentially unity spin-current transmission at room temperature due to considerably enhanced effective spin-mixing conductance of the interface. As a result, we obtain dampinglike spin-orbit torque efficiency per unit current density of up to 0.8 as detected by the standard technology ferromagnet FeCoB and others, which reaches the expected upper-limit spin Hall ratio of Pt. We establish that Pt/NiO and Pt-Hf/NiO are two energy-efficient, integration-friendly, and high-endurance spin-current generators that provide >100 times greater energy efficiency than sputter-deposited topological insulators BiSb and BiSe. Our finding will benefit spin-orbitronic research and advance spin-torque technologies.

Accepted in Physical Review Letters

References in corpus (40)

• Spin torque switching with the giant spin Hall effect of tantalum
• Spin Transfer Torque Generated by the Topological Insulator Bi_2Se_3
• Spin transfer torque devices utilizing the giant spin Hall effect of tungsten
• Symmetry and magnitude of spin-orbit torques in ferromagnetic heterostructures
• Study of Intrinsic Spin Hall Effect and Orbital Hall Effect in 4d- and 5d- Transition Metals
• Spin Pumping and Inverse Spin Hall Effect in Platinum: The Essential Role of Spin-Memory Loss at Metallic Interfaces
• Quantitative study of the spin Hall magnetoresistance in ferromagnetic insulator/normal metal hybrids
• Current induced torques and interfacial spin-orbit coupling: Semiclassical Modeling
• Dependence of the Efficiency of Spin Hall Torque on the Transparency of Pt-Ferromagnetic Layer Interfaces
• Room-temperature perpendicular magnetization switching through giant spin-orbit torque from sputtered BixSe(1-x) topological insulator material
• A conductive topological insulator with colossal spin Hall effect for ultra-low power spin-orbit-torque switching
• Spin torque study of the spin Hall conductivity and spin diffusion length in platinum thin films with varying resistivity
• Interplay of spin-orbit torque and thermoelectric effects in ferromagnet/normal metal bilayers
• Antiferromagnonic Spin Transport from Y${}_3$Fe${}_5$O${}_{12}$ into NiO
• Tuning the spin Hall effect of Pt from the moderately dirty to the superclean regime
• Enhancement of Thermally Injected Spin Current through an Antiferromagnetic Insulator
• Spin Transport at Interfaces with Spin-Orbit Coupling: Phenomenology
• Single-shot dynamics of spin-orbit torque and spin transfer torque switching in three-terminal magnetic tunnel junctions
• First-principles study of magnetization relaxation enhancement and spin-transfer in thin magnetic films
• Highly efficient spin current generation by the spin Hall effect in Au${}_{1-x}$Pt${}_x$
• Interface enhancement of Gilbert damping from first-principles
• Effective spin-mixing conductance of heavy-metal-ferromagnet interfaces
• Spin-current probe for phase transition in an insulator
• Spin-orbit torques in heavy metal/ferromagnet bilayers with varying strength of interfacial spin-orbit coupling
• Observation of inverse spin Hall effect in bismuth selenide
• Conduction of spin currents through insulating oxides
• Nanosecond-timescale low error switching of in-plane magnetic tunnel junctions through dynamic Oersted-field assisted spin-Hall effect
• Anti-damping spin transfer torque through epitaxial Nickel oxide
• On the origin of field-like spin-orbit torques in heavy metal-ferromagnet-oxide thin film heterostructures
• Transformation of spin current by antiferromagnetic insulators
• The spin Hall effect of Bi-Sb alloys driven by thermally excited Dirac-like electrons
• Spin-memory loss due to spin-orbit coupling at ferromagnet/heavy-metal interfaces: Ab initio spin-density matrix approach
• Enhancing spin-orbit torque by strong interfacial scattering from ultra-thin insertion layers
• Thermal Stability and Anisotropic Sublimation of Two-Dimensional Colloidal Bi2Te3 and Bi2Se3 Nanocrystals
• Coherent transfer of spin angular momentum by evanescent spin waves within antiferromagnetic NiO
• Maximizing the spin-orbit torque efficiency of Pt/Ti multilayers by optimization of the tradeoff between the intrinsic spin Hall conductivity and carrier lifetime
• Enhancement of spin transparency by interfacial alloying
• Energy-efficient ultrafast SOT-MRAMs based on low-resistivity spin Hall metal Au0.25Pt0.75
• Ballistic spin transport in the presence of interfaces with strong spin-orbit coupling
• Origin of Strong Two-Magnon Scattering in Heavy Metal/Ferromagnet/Oxide Heterostructures

Cited by in corpus (11)

• Maximizing Spin-Orbit Torque Generated by the Spin Hall Effect of Pt
• Switching of Perpendicular Magnetization by Spin-Orbit Torque
• Toward 100% Spin-Orbit Torque Efficiency with High Spin-Orbital Hall Conductivity Pt-Cr Alloys
• Strong variation of spin-orbit torques with relative spin relaxation rates in ferrimagnets
• Strong Spin-Orbit Torque Induced by the Intrinsic Spin Hall Effect in Cr1-xPtx
• Boosting spin-orbit torque efficiency in spin-current generator/magnet/oxide superlattices
• Charge-Spin Interconversion in Epitaxial Pt Probed by Spin-Orbit Torques in a Magnetic Insulator
• Calculating the spin memory loss at Cu$|$metal interfaces from first principles
• Interface transparency to orbital current
• Substrate-induced spin-torque-like signal in spin-torque ferromagnetic resonance measurement
• Enhancing z spin generation in trivial spin Hall materials for scalable, energy-efficient, field-free, complete spin-orbit torque switching applications