Electronically driven spin-reorientation transition of the correlated polar metal Ca${}_3$Ru${}_2$O${}_7$

Abstract

Polar distortions in solids give rise to the well-known functionality of switchable macroscopic polarisation in ferroelectrics and, when combined with strong spin-orbit coupling, can mediate giant spin splittings of electronic states. While typically found in insulators, ferroelectric-like distortions can remain robust against increasing itineracy, giving rise to so-called "polar metals". Here, we investigate the temperature-dependent electronic structure of Ca${}_3$Ru${}_2$O${}_7$, a correlated oxide metal in which octahedral tilts and rotations combine to mediate pronounced polar distortions. Our angle-resolved photoemission measurements reveal the destruction of a large hole-like Fermi surface upon cooling through a coupled structural and spin-reorientation transition at 48 K, accompanied by a sudden onset of quasiparticle coherence. We demonstrate how these result from band hybridisation mediated by a hidden Rashba-type spin-orbit coupling. This is enabled by the bulk structural distortions and unlocked when the spin reorients perpendicular to the local symmetry-breaking potential at the Ru sites. We argue that the electronic energy gain associated with the band hybridisation is actually the key driver for the phase transition, reflecting a delicate interplay between spin-orbit coupling and strong electronic correlations, and revealing a new route to control magnetic ordering in solids.

Contains 6+5 pages, including supplementary information

References in corpus (4)

• Maximal Rashba-like spin splitting via kinetic energy-driven inversion symmetry breaking
• Spin-valve effect and magnetoresistivity in single crystalline Ca3Ru2O7
• Evidence for the weakly coupled electron mechanism in an Anderson-Blount polar metal
• Existence of electron and hole pockets and partial gap opening in the correlated semimetal Ca3Ru2O7

Cited by in corpus (20)

• Hierarchy of Lifshitz transitions in the surface electronic structure of Sr${}_2$RuO${}_4$ under uniaxial compression
• Hybrid d/p-wave altermagnetism in Ca${}_3$Ru${}_2$O${}_7$ and strain-controlled spin splitting
• Altermagnetism in Two Dimensional Ca${}_2$RuO${}_4$ Perovskite
• Spontaneous cycloidal order mediating a spin-reorientation transition in a polar metal
• Strain control of a bandwidth-driven spin reorientation in Ca${}_3$Ru${}_2$O${}_7$
• Thermodynamic and electron-transport properties of Ca3Ru2O7 from first-principles phonon calculations and Boltzmann transport theory
• Two-carrier Magnetoresistance: Applications to Ca${}_3$Ru${}_2$O${}_7$
• Spatial inhomogeneity and the metal-insulator transition in Ca${}_3$(Ru${}_{1-x}$Ti${}_x$)${}_2$O${}_7$
• Altermagnetism, ARPES, symmetry, non-relativistic band splitting
• Nonlinear Transport Signatures of Hidden Symmetry Breaking in a Weyl Altermagnet
• The power of flexible lattice in Ca3Ru2O7: Exquisite control of the electrical transport via anisotropic magnetostriction
• Photoinduced phase switching at a Mott insulator-to-metal transition
• Exotic magnetic anisotropy near digitized dimensional Mott boundary
• Prediction of Room Temperature Electric Field Reversal of Magnetization in the Family of $A_4{B}_3{\mathrm{O}}_9$ Layered Oxides
• Probing Hidden Symmetry and Altermagnetism with Sub-Picometer Sensitivity via Nonlinear Transport
• Evidence for bootstrap percolation dynamics in a photo-induced phase transition
• Critical magnetic fluctuations in the layered ruthenates Ca${}_2$RuO${}_4$ and Ca${}_3$Ru${}_2$O${}_7$
• A simplified method characterizing magnetic ordering modulated photo-thermoelectric response in noncentrosymmetric semimetal Ca3Ru2O7
• Autferroicity: concept, candidates, and applications
• Charge disproportionation as a possible mechanism towards polar antiferromagnetic metal in molecular orbital crystal