Two-dimensional J.sub.eff./sub.=1/2 antiferromagnetic insulator unraveled from interlayer exchange coupling in artificial perovskite iridate superlattices

0484697 - FZÚ 2018 RIV US eng J - Journal Article
Hao, L. - Meyers, D. - Frederick, C. - Fabbris, G. - Yang, J. - Traynor, N. - Horák, L. - Kriegner, Dominik - Choi, Y. - Kim, J.-W. - Haskel, D. - Ryan, P.J. - Dean, M.P.M. - Liu, J.
Two-dimensional J_eff=1/2 antiferromagnetic insulator unraveled from interlayer exchange coupling in artificial perovskite iridate superlattices.
Physical Review Letters. Roč. 119, č. 2 (2017), s. 1-6, č. článku 027204. ISSN 0031-9007. E-ISSN 1079-7114
R&D Projects: GA ČR GB14-37427G; GA MŠMT EF16_013/0001405
Grant - others:OP VVV - LNSM(XE) CZ.02.1.01/0.0/0.0/16_013/0001405
Institutional support: RVO:68378271
Keywords : Heisenberg-antiferromagnet * optical-properties * Sr₂IrO₄ * lattice * oxides
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 8.839, year: 2017

We report an experimental investigation of the two-dimensional Jeff ¼ 1=2 antiferromagnetic Mott insulator by varying the interlayer exchange coupling in [ðSrIrO3 Þ 1, ðSrTiO3 Þ m] (m ¼ 1, 2 and 3) superlattices. Although all samples exhibited an insulating ground state with long-range magnetic order, temperature-dependent resistivity measurements showed a stronger insulating behavior in the m ¼ 2 and m ¼ 3 samples than the m ¼ 1 sample which displayed a clear kink at the magnetic transition. This difference indicates that the blocking effect of the excessive SrTiO3 layer enhances the effective electronelectron correlation and strengthens the Mott phase. The significant reduction of the Néel temperature from 150 K for m ¼ 1 to 40 K for m ¼ 2 demonstrates that the long-range order stability in the former is boosted by a substantial interlayer exchange coupling.
Permanent Link: http://hdl.handle.net/11104/0279834