Exploration of Altermagnetism in $\mathrm{Ru}{\mathrm{O}}_2$

Abstract

The fundamental role of magnetic materials in modern science and technology has driven a rapid surge in research on unconventional magnetism in recent years. In particular, altermagnets, which simultaneously exhibit zero net magnetization in real space and anisotropic spin splitting in momentum space, have garnered significant interest for both fundamental physics and technological applications. Among these, $\mathrm{Ru}{\mathrm{O}}_2$ stands as the pioneering and most extensively studied altermagnet. While the intrinsic magnetic order of $\mathrm{Ru}{\mathrm{O}}_2$ is still a subject of active debate, numerous exotic phenomena characteristic of altermagnetism have been observed in $\mathrm{Ru}{\mathrm{O}}_2$ samples. In this review, we explore each facet of the altermagnetism through specific case studies in $\mathrm{Ru}{\mathrm{O}}_2$, systematically surveying its crystal and magnetic structures, electronic band properties, and transport phenomena. We critically assess the debate surrounding the intrinsic magnetism in $\mathrm{Ru}{\mathrm{O}}_2$, incorporating evidence from altermagnetic signatures in transport, as well as contrasting results from magnetic and spectroscopic measurements. Finally, possible future research directions in this field are discussed.

27 pages, 8 figures, 1 table

References in corpus (112)

• Quantum Spin Hall Effect in Graphene
• Anomalous Hall effect
• Weyl and Dirac Semimetals in Three Dimensional Solids
• Electrical Control of 2D Magnetism in Bilayer CrI3
• Coupling of two superconductors through a ferromagnet : evidence for a pi-junction
• First Principles Calculation of Anomalous Hall Conductivity in Ferromagnetic bcc Fe
• Crystal Hall effect in Collinear Antiferromagnets
• Electric-field switching of two-dimensional van der Waals magnets
• Anomalous Hall effect arising from noncollinear antiferromagnetism
• Dirac Cone Protected by Non-Symmorphic Symmetry and 3D Dirac Line Node in ZrSiS
• Topological Node-Line Semimetal in Three Dimensional Graphene Networks
• Topological nodal line semimetals
• Dirac Semimetals in Two Dimensions
• Observation of the Anomalous Hall Effect in a Collinear Antiferromagnet
• Giant momentum-dependent spin splitting in centrosymmetric low Z antiferromagnets
• Efficient Electrical Spin-Splitter Based on Non-Relativistic Collinear Antiferromagnetism
• Momentum-Dependent Spin Splitting by Collinear Antiferromagnetic Ordering
• Multifunctional Antiferromagnetic Materials with Giant Piezomagnetism and Noncollinear Spin Current
• Observation of spin splitting torque in a collinear antiferromagnet RuO2
• Broken Kramers' degeneracy in altermagnetic MnTe
• Large magneto-optical Kerr effect and imaging of magnetic octupole domains in an antiferromagnetic metal
• Spin current generation in organic antiferromagnets
• Altermagnetism: Exploring New Frontiers in Magnetism and Spintronics
• Tilted spin current generated by the collinear antiferromagnet RuO2
• Observation of Topological Nodal Fermion Semimetal Phase in ZrSiS
• Topological Semimetals Predicted from First-principles Calculations
• Non-collinear Antiferromagnets and the Anomalous Hall Effect
• Observation of spin-splitter torque in collinear antiferromagnetic RuO${}_2$
• Prediction of unconventional magnetism in doped FeSb2
• Antiferromagnetism in RuO${}_2$ as $d$-wave Pomeranchuk instability
• Discovery of Dirac Node Arcs in PtSn4
• Observation of Giant Band Splitting in Altermagnetic MnTe
• Itinerant Antiferromagnetism in RuO${}_2$
• Topological Semimetals from first-principles
• Observation of plaid-like spin splitting in a noncoplanar antiferromagnet
• Crystal Thermal Transport in Altermagnetic RuO2
• Classification of atomic-scale multipoles under crystallographic point groups and application to linear response tensors
• Topological Nodal Line Semimetals in CaP3 family of materials
• Large band-splitting in $g$-wave type altermagnet CrSb
• Fermi liquid instabilities in the spin channel
• Discovery of a metallic room-temperature d-wave altermagnet KV2Se2O
• dc Josephson Effect in Altermagnets
• Oscillations of the superconducting critical current in Nb-Cu-Ni-Cu-Nb junctions
• Anomalous Antiferromagnetism in Metallic RuO${}_2$ Determined by Resonant X-ray Scattering
• Finite-momentum Cooper pairing in proximitized altermagnets
• Giant topological Hall effect in correlated oxide thin films
• Dirac nodal lines and induced spin Hall effect in metallic rutile oxides
• Nonmagnetic Ground State in RuO${}_2$ Revealed by Muon Spin Rotation
• Hourglass Dirac Chain Metal in Rhenium Dioxide
• Gate-controllable magneto-optic Kerr effect in layered collinear antiferromagnets
• Absence of altermagnetic spin splitting character in rutile oxide RuO${}_2$
• Large magneto-optical Kerr effect in noncollinear antiferromagnets Mn${}_{3}X$ ($X$ = Rh, Ir, or Pt)
• Andreev reflection at the altermagnet-superconductor interface
• Crystal-symmetry-paired spin-valley locking in a layered room-temperature antiferromagnet
• Spin-split collinear antiferromagnets: a large-scale ab-initio study
• Topological transition from nodal to nodeless Zeeman splitting in altermagnets
• Phase-shifted Andreev levels in an altermagnet Josephson junction
• Spontaneous topological Hall effect induced by non-coplanar antiferromagnetic order in intercalated van der Waals materials
• Néel Spin Currents in Antiferromagnets
• Anomalous Hall effect in $\kappa$-type organic antiferromagnets
• Strain-stabilized superconductivity
• Minimal Models for Altermagnetism
• Saturation of the anomalous Hall effect at high magnetic fields in altermagnetic RuO2
• Mirror Chern Bands and Weyl Nodal Loops in Altermagnets
• Fragility of the magnetic order in the prototypical altermagnet RuO${}_2$
• Spin-order dependent anomalous Hall effect and magneto-optical effect in noncollinear antiferromagnets Mn${}_{3}X$N ($X$ = Ga, Zn, Ag, and Ni)
• Electrically Controllable Crystal Chirality Magneto-Optical Effects in Collinear Antiferromagnets
• Anisotropy of the anomalous Hall effect in the altermagnet candidate Mn${}_5$Si${}_3$ films
• Altermagnetic anomalous Hall effect emerging from electronic correlations
• Creation and Manipulation of Higher-Order Topological States by Altermagnets
• Superconductivity in Uniquely Strained RuO${}_2$ Films
• Crystal facet orientated Altermagnets for detecting ferromagnetic and antiferromagnetic states by giant tunneling magnetoresistance effect
• 0-pi transitions in Josephson junctions with antiferromagnetic interlayers
• Tunneling magnetoresistance in magnetic tunnel junctions with a single ferromagnetic electrode
• Intrinsic anomalous Hall effect in altermagnets
• Topological semimetals studied by ab initio calculations
• Orientation-dependent Josephson effect in spin-singlet superconductor/altermagnet/spin-triplet superconductor junctions
• Finite momentum Cooper pairing in 3D topological insulator Josephson junctions
• $\phi$ Josephson junction induced by altermagnetism
• Field-free Josephson diode effect in altermagnet/normal metal/altermagnet junctions
• Experimental observation of bulk nodal lines and electronic surface states in ZrB${}_2$
• Comparing the anomalous Hall effect and the magneto-optical Kerr effect through antiferromagnetic phase transitions in Mn${}_3$Sn
• Tunable band topology and optical conductivity in altermagnets
• Fermi-liquid behavior of non-altermagnetic RuO${}_2$
• Tunable second harmornic in altermagnetic Josephson junctions
• Crystal structure and absence of magnetic order in single crystalline RuO${}_2$
• Odd-parity Magnetism Driven by Antiferromagnetic Exchange
• Magneto-optic and transverse transport properties of non-collinear antiferromagnets
• Design of altermagnetic models from spin clusters
• Spontaneous Crystal Thermal Hall Effect in Insulating Altermagnets
• Altermagnetic variants in thin films of Mn5Si3
• Fragile Unconventional Magnetism in RuO${}_2$ by Proximity to Landau-Pomeranchuk Instability
• Spin-polarized Specular Andreev Reflections in Altermagnets
• Incomplete Andreev reflection in a clean Superconductor/Ferromagnet/Superconductor junction
• Strain-induced orbital energy shift in antiferromagnetic RuO2 revealed by resonant elastic x-ray scattering
• Spin-Splitting Magnetoresistance in Altermagnetic RuO2 Thin Films
• Multiband transport in RuO${}_2$
• Oxygen vacancy-driven orbital multichannel Kondo effect in Dirac nodal line metals IrO2 and RuO2
• Emergent Multiferroic Altermagnets and Spin Control via Noncollinear Molecular Polarization
• All-electrically controlled spintronics in altermagnetic heterostructures
• Evidence for single variant in altermagnetic RuO2(101) thin films
• Scaling Behavior of Magnetoresistance and Hall Resistivity in Altermagnet CrSb
• Universal Scaling Behavior of Transport Properties in Non-Magnetic RuO${}_2$
• Unveiling an in-plane Hall effect in rutile RuO${}_2$ films
• Symmetry-breaking induced surface magnetization in non-magnetic RuO${}_2$
• Anomalous-Hall Neel textures in altermagnetic materials
• Anomalous Magneto Optic Effects from an Antiferromagnet Topological-Insulator Heterostructure
• Ubiquitous van der Waals altermagnetism with sliding/moire ferroelectricity
• Origin of Anomalous Hall effect in Cr-doped RuO${}_2$
• Diagnosing Altermagnetic Phases through Quantum Oscillations
• First-principles study on tunnel magnetoresistance effect with Cr-doped RuO${}_2$ electrode
• Non-linear anomalous Edelstein response at altermagnetic interfaces

Cited by in corpus (1)

• Quantum oscillation fingerprints of altermagnetism in hole-doped RuO2