2018/09/30 by Chanchal Barman, Prashant Singh, Duane D. Johnson +1 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevlett.122.076401
published as Phys. Rev. Lett. 122, 076401 (2019) · 6 pages, 4 figures
arxiv created 2019/01/27 · arxiv updated 2019/02/27
Cerium-hexaboride (CeB6) f-electron compound displays a rich array of low-temperature magnetic phenomena, including `magnetically hidden' order, identified as multipolar in origin via advanced x-ray scattering. From first-principles electronic-structure results, we find that the antiferro-quadrupolar (AFQ) ordering in CeB6 arises from crystal-field splitting and yields band structure in agreement with experiments. With interactions of p-electrons between Ce and B6 being small, the electronic state of CeB6 is suitably described as Ce(4f1)3+(e-)(B6)2-. The AFQ state of orbital spins is caused by an exchange interaction induced through spin-orbit interaction, which also splits J=5/2 state into Γ8 ground state and Γ7 excited state. Within the smallest antiferromagnetic (111) configuration, an orbital-ordered AFQ state appears during charge self-consistency, and supports the appearance of `hidden' order. Hydrostatic pressure (either applied or chemically induced) stabilizes the AFM (AFQ) states over a ferromagnetic one, as observed at low temperatures.