All-in–all-out magnetic order and propagating spin waves in Sm2Ir2O7

DOI: 10.1103/PhysRevLett.117.037201

Authors: C. Donnerer (London Centre for Nanotechnology) , M. C. Rahn (University of Oxford) , M. Moretti Sala (ESRF) , J. g. Vale (University College London; Ecole Polytechnique Federale de Lausanne (EPFL)) , D. Pincini (University College London; Diamond Light Source) , J. Strempfer (DESY) , M. Krisch (ESRF) , D. Prabhakaran (University of Oxford) , A. T. Boothroyd (University of Oxford) , D. F. Mcmorrow (University College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Review Letters , VOL 117

State: Published (Approved)
Published: July 2016

Abstract: Using resonant magnetic x-ray scattering we address the unresolved nature of the magnetic ground state and the low-energy effective Hamiltonian of Sm2Ir2O7, a prototypical pyrochlore iridate with a finite temperature metal-insulator transition. Through a combination of elastic and inelastic measurements, we show that the magnetic ground state is an all-in–all-out (AIAO) antiferromagnet. The magnon dispersion indicates significant electronic correlations and can be well described by a minimal Hamiltonian that includes Heisenberg exchange [J=27.3(6)  meV ] and Dzyaloshinskii-Moriya interactions [D=4.9(3)  meV ], which provides a consistent description of the magnetic order and excitations. In establishing that Sm2Ir2 O7 has the requisite inversion symmetry preserving AIAO magnetic ground state, our results support the notion that pyrochlore iridates may host correlated Weyl semimetals.

Journal Keywords: Antiferromagnetism; Dzyaloshinskii-Moriya interaction; Frustrated magnetism; Spin-orbit coupling; Iridates; Pyrochlores; Weyl semimetal; Resonant inelastic x-ray scattering; X-ray resonant magnetic scattering

Diamond Keywords: Antiferromagnetism

Subject Areas: Physics, Materials

Facility: ID20 at ESRF; PETRA III at DESY

Added On: 01/12/2016 14:37

Discipline Tags:

Quantum Materials Physics Magnetism Materials Science

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