Electronically driven spin-reorientation transition of the correlated polar metal Ca3Ru2O7

Research output: Contribution to journalArticle

Abstract

The interplay between spin-orbit coupling and structural inversion symmetry breaking in solids has generated much interest due to the nontrivial spin and magnetic textures which can result. Such studies are typically focused on systems where large atomic number elements lead to strong spin-orbit coupling, in turn rendering electronic correlations weak. In contrast, here we investigate the temperature-dependent electronic structure of Ca3Ru2O7, a 4d oxide metal for which both correlations and spin-orbit coupling are pronounced and in which octahedral tilts and rotations combine to mediate both global and local inversion symmetry-breaking polar distortions. Our angle-resolved photoemission measurements reveal the destruction of a large hole-like Fermi surface upon cooling through a coupled structural and spinreorientation transition at 48 K, accompanied by a sudden onset of quasiparticle coherence. We demonstrate how these result from band hybridization 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 hybridization is actually the key driver for the phase transition, reflecting a delicate interplay between spin-orbit coupling and strong electronic correlations and revealing a route to control magnetic ordering in solids.

Details

Authors
  • Igor Marković
  • Matthew D. Watson
  • Oliver J. Clark
  • Federico Mazzola
  • Edgar Abarca Morales
  • Chris A. Hooley
  • Helge Rosner
  • Craig M. Polley
  • Thiagarajan Balasubramanian
  • Saumya Mukherjee
  • Naoki Kikugawa
  • Dmitry A. Sokolov
  • Andrew P. Mackenzie
  • Phil D.C. King
Organisations
External organisations
  • Max Planck Institute for Chemical Physics of Solids
  • Diamond Light Source
  • National Institute for Material Science
  • University of St Andrews
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Sciences

Keywords

  • Angle-resolved photoemission, Correlated oxide, Magnetism, Rashba spin-orbit, Ruthenate
Original languageEnglish
Pages (from-to)15524-15529
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume117
Issue number27
Publication statusPublished - 2020
Publication categoryResearch
Peer-reviewedYes