TY - JOUR
T1 - Cobalt-based pyroxenes
T2 - A new playground for Kitaev physics
AU - Maksimov, Pavel A.
AU - Ushakov, Alexey V.
AU - Gubkin, Andrey F.
AU - Redhammer, Günther J.
AU - Winter, Stephen M.
AU - Kolesnikov, Alexander I.
AU - Dos Santos, Antonio M.
AU - Gai, Zheng
AU - McGuire, Michael A.
AU - Podlesnyak, Andrey
AU - Streltsov, Sergey V.
PY - 2024/10/22
Y1 - 2024/10/22
N2 - Recent advances in the study of cobaltites have unveiled their potential as a promising platform for realizing Kitaev physics in honeycomb systems and the Ising model in weakly coupled chain materials. In this manuscript, we explore the magnetic properties of pyroxene SrCoGe[Formula: see text]O[Formula: see text] using a combination of neutron scattering, ab initio methods, and linear spin-wave theory. Through careful examination of inelastic neutron scattering powder spectra, we propose a modified Kitaev model to accurately describe the twisted chains of edge-sharing octahedra surrounding Co[Formula: see text] ions. The extended Kitaev-Heisenberg model, including a significant anisotropic bond-dependent exchange term with [Formula: see text], is identified as the key descriptor of the magnetic interactions in SrCoGe[Formula: see text]O[Formula: see text]. Furthermore, our heat capacity measurements reveal an effect of an external magnetic field (approximately 13 T) which shifts the system from a fragile antiferromagnetic ordering with [Formula: see text] K to a field-induced state. We argue that pyroxenes, particularly those modified by substituting Ge with Si and its less extended [Formula: see text] orbitals, emerge as a platform for the Kitaev model. This opens up possibilities for advancing our understanding of Kitaev physics.
AB - Recent advances in the study of cobaltites have unveiled their potential as a promising platform for realizing Kitaev physics in honeycomb systems and the Ising model in weakly coupled chain materials. In this manuscript, we explore the magnetic properties of pyroxene SrCoGe[Formula: see text]O[Formula: see text] using a combination of neutron scattering, ab initio methods, and linear spin-wave theory. Through careful examination of inelastic neutron scattering powder spectra, we propose a modified Kitaev model to accurately describe the twisted chains of edge-sharing octahedra surrounding Co[Formula: see text] ions. The extended Kitaev-Heisenberg model, including a significant anisotropic bond-dependent exchange term with [Formula: see text], is identified as the key descriptor of the magnetic interactions in SrCoGe[Formula: see text]O[Formula: see text]. Furthermore, our heat capacity measurements reveal an effect of an external magnetic field (approximately 13 T) which shifts the system from a fragile antiferromagnetic ordering with [Formula: see text] K to a field-induced state. We argue that pyroxenes, particularly those modified by substituting Ge with Si and its less extended [Formula: see text] orbitals, emerge as a platform for the Kitaev model. This opens up possibilities for advancing our understanding of Kitaev physics.
KW - frustrated magnetism
KW - inelastic neutron scattering
KW - Kitaev model
KW - pyroxenes
UR - http://www.scopus.com/inward/record.url?scp=85206872469&partnerID=8YFLogxK
U2 - 10.1073/pnas.2409154121
DO - 10.1073/pnas.2409154121
M3 - Article
C2 - 39423242
AN - SCOPUS:85206872469
SN - 0027-8424
VL - 121
SP - e2409154121
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 43
ER -