Hyperhoneycomb Iridate beta-Li2IrO3 as a Platform for Kitaev Magnetism

Autor(es)

Takayama, T. ^{[1, 2, 3]} ; Kato, A. ^{[2, 3]} ; Dinnebier, R. ^[1] ; Nuss, J. ^[1] ; Kono, H. ^{[2, 3]} ; Veiga, L. S. I. ^{[4, 5, 6]} ; Fabbris, G. ^{[6, 7]} ; Haskel, D. ^[6] ; Takagi, H. ^{[1, 2, 3]}

Afiliação do(s) autor(es)

^[1] Max Planck Inst Solid State Res, D-70569 Stuttgart - Germany

^[2] Univ Tokyo, Dept Phys, Tokyo 1130033 - Japan

^[3] Univ Tokyo, Dept Adv Mat, Tokyo 1130033 - Japan

^[4] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP - Brazil

^[5] Lab Nacl Luz Sincrotron, BR-13083970 Campinas, SP - Brazil

^[6] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 - USA

^[7] Washington Univ, Dept Phys, St Louis, MO 63130 - USA

• Tipo de documento: Artigo Científico
• Fonte: Physical Review Letters; v. 114, n. 7 FEB 19 2015.
• Citações Web of Science: 171

Resumo

A complex iridium oxide beta-Li2IrO3 crystallizes in a hyperhoneycomb structure, a three-dimensional analogue of honeycomb lattice, and is found to be a spin-orbital Mott insulator with J(eff) = 1/2 moment. Ir ions are connected to the three neighboring Ir ions via Ir-O-2-Ir bonding planes, which very likely gives rise to bond-dependent ferromagnetic interactions between the J(eff) = 1/2 moments, an essential ingredient of Kitaev model with a spin liquid ground state. Dominant ferromagnetic interaction between J(eff) = 1/2 moments is indeed confirmed by the temperature dependence of magnetic susceptibility chi(T) which shows a positive Curie-Weiss temperature theta(CW) similar to +40 K. A magnetic ordering with a very small entropy change, likely associated with a noncollinear arrangement of J(eff) = 1/2 moments, is observed at T-c = 38 K. With the application of magnetic field to the ordered state, a large moment of more than 0.35 mu(B)/Ir is induced above 3 T, a substantially polarized J(eff) = 1/2 state. We argue that the close proximity to ferromagnetism and the presence of large fluctuations evidence that the ground state of hyperhoneycomb beta-Li2IrO3 is located in close proximity of a Kitaev spin liquid. (AU)

• Processo FAPESP: 13/14338-3 - Competição entre supercondutividade e magnetismo em sistemas sob pressão e filmes finos
• Beneficiário: Larissa Sayuri Ishibe Veiga
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado