Altermagnetism and superconductivity in a multiorbital t-J model

Abstract

Motivated by exploring doped multi-orbital antiferromagnets (AFMs) and altermagnets (ALMs) we explore minimal $t$-$J$ models on the square-octagon lattice which favor such collinear magnetic orders in the regime where spin exchange dominates. While the AFM order breaks translational and time-reversal symmetries, the ALM state (equivalently, a `$d$-wave ferromagnet') features multipolar order which separately breaks time-reversal and crystal rotation symmetries but preserves their product leading to spin-split bands with zero net magnetization. We study the mean field phase diagram of these models as we vary doping and interactions, discovering regimes of weak and strong ALM order, superconductivity including uniform $s$-wave and $d$-wave pairing states, incipient $d$-wave pair density wave order, and phases with coexisting singlet-triplet pairing and AFM/ALM orders which appear unstable to phase separation and could host stripe order with longer-range interactions. We study the mean field phase diagram of these multiorbital models as we vary doping and interactions, discovering two types of ALM order: (i) itinerant weak-coupling ALM metals driven by quasi-1D van Hove singularities, as well as (ii) strong ALM order at half-filling. We also find regimes of superconductivity including uniform $s$-wave and $d$-wave pairing states, incipient $d_{xy}$-wave pair density wave order, and uniform phases with coexisting singlet-triplet pairing and ALM order. Our inhomogeneous mean field theory approach reveals that the coexistence phases are unstable to phase separation, but longer-range interactions could lead to stripe order. Our results may be relevant to doping or pressure studies of multiorbital ALM materials.

14 pages, 13 figures

References in corpus (29)

• Superconductivity near 80 Kelvin in single crystals of La3Ni2O7 under pressure
• Magnetism, superconductivity, and pairing symmetry in Fe-based superconductors
• Strong Correlations and Magnetic Frustration in the High Tc Iron Pnictides
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Direct observation of altermagnetic band splitting in CrSb thin films
• Orbital-driven nematicity in FeSe
• Observation of Giant Band Splitting in Altermagnetic MnTe
• Topological Superconductivity in Two-Dimensional Altermagnetic Metals
• Finite-momentum Cooper pairing in proximitized altermagnets
• Landau Theory of Altermagnetism
• Nickelate superconductors $--$ Multiorbital nature and spin freezing
• Altermagnetic Routes to Majorana Modes in Zero Net Magnetization
• Two-dimensional altermagnets: Superconductivity in a minimal microscopic model
• Topological transition from nodal to nodeless Zeeman splitting in altermagnets
• Altermagnetic superconducting diode effect
• Two-band model for magnetism and superconductivity in nickelates
• Orbital Selective Superconductivity in a Two-band Model of Infinite-Layer Nickelates
• Spontaneous Formation of Altermagnetism from Orbital Ordering
• Anisotropy of the anomalous Hall effect in the altermagnet candidate Mn${}_5$Si${}_3$ films
• Quantum Spin Hall Effect in 2D Transition Metal Dichalcogenide Haeckelites
• Realizing Altermagnetism in Fermi-Hubbard Models with Ultracold Atoms
• Pair-Density-Wave Superconducting States and Electronic Liquid Crystal Phases
• Development of a two-particle self-consistent method for multi-orbital systems and its application to unconventional superconductors
• Quasiclassical theory of superconducting spin-splitter effects and spin-filtering via altermagnets
• Dynamic paramagnon-polarons in altermagnets
• Many-body effects on superconductivity mediated by double-magnon processes in altermagnets
• Nematic and spin-charge orders driven by hole-doping a charge-transfer insulator
• Unified description of cuprate superconductors using four-band $d$-$p$ model
• Effects of orbital selective dynamical correlation on the spin susceptibility and superconducting symmetries in Sr${}_2$RuO${}_4$

Cited by in corpus (29)

• Superconducting phenomena in systems with unconventional magnets
• Unconventional p-wave and finite-momentum superconductivity induced by altermagnetism through the formation of Bogoliubov Fermi surface
• Altermagnetic phase transition in a Lieb metal
• Pair Density Waves and Supercurrent Diode Effect in Altermagnets
• Tuning of altermagnetism by strain
• Finite-momentum superconductivity in two-dimensional altermagnets with a Rashba-type spin-orbit coupling
• Coexistence of $p$-wave magnetism and superconductivity
• Adatom engineering magnetic order in superconductors: Applications to altermagnetic superconductivity
• Self-consistent theory of $2\times 2$ pair density waves in kagome superconductors
• Spin and pair density waves in 2D altermagnetic metals
• Phonon-mediated spin-polarized superconductivity in altermagnets
• Intra-unit-cell singlet pairing mediated by altermagnetic fluctuations
• Conditions for orbital selective altermagnetism in Sr${}_2$RuO${}_4$: tight binding model, similarities with cuprates and implications on superconductivity
• Fractionalized Altermagnets: from neighboring and altermagnetic spin-liquids to spin-symmetric band splitting
• Exploring d-Wave Magnetism in Cuprates from Oxygen Moments
• Altermagnetism in Heavy Fermion Systems: Mean-Field study on Kondo Lattice
• Light-induced odd-parity altermagnets on dimerized lattices
• Quantum Lifshitz points in an altermagnetic metal
• Energy Dispersion, Superconductivity and Magnetic Fluctuations in Stacked Altermagnetism Materials
• Odd-parity altermagnetism through sublattice currents: From Haldane-Hubbard model to general bipartite lattices
• Spin-dependent quasiparticle lifetimes in altermagnets
• Inherent momentum-dependent gap structure of altermagnetic superconductors
• Quantum critical scaling of altermagnetism
• Quantum fluctuations in two-dimensional altermagnets
• Van-Hove singularities and competing instabilities in an altermagnetic metal
• Spontaneous emergence of altermagnetism in the single-orbital extended Hubbard model
• Spin triplet pairing by suppressing altermagnetism
• Electric field controlled second-order anomalous Hall effect in altermagnets
• Superconducting States and Intertwined Orders in Metallic Altermagnets