Unconventional superconductivity in altermagnets with spin-orbit coupling

Abstract

We investigate some possible symmetries of the superconducting state that emerges in three-dimensional altermagnets in the presence of spin-orbit coupling. We demonstrate within a weak-coupling approach that these altermagnets, which naturally possess an order modulated by a vector form factor ${\mathbf{g}}_{\mathbf{k}}$, favor spin-triplet superconductivity described by gap functions given by $\mathbf{d}(\mathbf{k})=\mathbf{u}(\mathbf{k})\times {\mathbf{g}}_{\mathbf{k}}$, where $\mathbf{u}(\mathbf{k})=-\mathbf{u}(-\mathbf{k})$. Consequently, this singles out $f$-wave spin-triplet superconductivity as the most favorable pairing state to appear in the vicinity of $d$-wave altermagnetism. Furthermore, we obtain that the combination of spin-singlet superconducting states with altermagnetism gives rise to Bogoliubov-Fermi surfaces, which are protected by a ${\mathbb{Z}}_2$ topological invariant. Using a Ginzburg-Landau analysis, we show that, for a class of spin-orbit coupled altermagnetic models, a superconducting phase is expected to appear at low temperatures as an intertwined $d+if$ state, thus breaking time-reversal symmetry spontaneously.

7 pages, 3 figures; Supplemental Material: 9 pages, 3 figures

References in corpus (14)

• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Broken Kramers' degeneracy in altermagnetic MnTe
• Prediction of unconventional magnetism in doped FeSb2
• Classification of reflection symmetry protected topological semimetals and nodal superconductors
• Bogoliubov Fermi surfaces in superconductors with broken time-reversal symmetry
• dc Josephson Effect in Altermagnets
• Topological Superconductivity in Two-Dimensional Altermagnetic Metals
• Finite-momentum Cooper pairing in proximitized altermagnets
• Landau Theory of Altermagnetism
• Pairing State with a time-reversal symmetry breaking in FeAs based superconductors
• Two-dimensional altermagnets: Superconductivity in a minimal microscopic model
• Topological transition from nodal to nodeless Zeeman splitting in altermagnets
• Altermagnetic superconducting diode effect
• Topological Blount's theorem of odd-parity superconductors

Cited by in corpus (20)

• Superconducting phenomena in systems with unconventional magnets
• 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
• Adatom engineering magnetic order in superconductors: Applications to altermagnetic superconductivity
• Spin and pair density waves in 2D altermagnetic metals
• Intra-unit-cell singlet pairing mediated by altermagnetic fluctuations
• Unconventional superconductivity of an altermagnetic metal: Polarized BCS and inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov states
• Fractionalized Altermagnets: from neighboring and altermagnetic spin-liquids to spin-symmetric band splitting
• Floquet engineering triplet superconductivity in superconductors with spin-orbit coupling or altermagnetism
• Light-induced odd-parity altermagnets on dimerized lattices
• Light-induced Floquet spin-triplet Cooper pairs in unconventional magnets
• Magnetic-field-tuned randomness in inhomogeneous altermagnets
• Efficiency of the superconducting diode effect of pair-density-wave states in two-dimensional $d$-wave altermagnets
• Inherent momentum-dependent gap structure of altermagnetic superconductors
• Engineering subgap states in superconductors by the symmetry of altermagnetism
• Altermagnetism-driven FFLO superconductivity in finite-filling 2D lattices
• Cartesian Nodal Lines and Magnetic Kramers Weyl Nodes in Spin-Split Antiferromagnets
• Spin transport in a normal meta-altermagnetic superconducting nanowire junction
• Spin triplet pairing by suppressing altermagnetism