Spatial anisotropy of the quantum spin liquid system YbMgGaO4 revealed by ab initio calculations. (18th October 2019)

• Record Type: Journal Article
• Authors: Lima, Matheus P
• Is Part Of: Journal of physics. Volume 32:Number 2(2020)
• Publication Date: 2019-10-18
• Subjects: quantum-spin-liquid -- density-functional-theory -- magnetism; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ab4ab6
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: YbMgGaO4 was recently proposed as a promising quantum-spin-liquid candidate material. However, some details of its structure, such as those related to a spatial anisotropy, were not completely understood. In this work, we perform ab initio calculations based on density-functional-theory to investigate the structural, the electronic and the magnetic properties of YbMgGaO4 . The geometrical model was constructed to take into account disorder effects produced by the random distribution of Ga and Mg along the lattice. We found a substantial spatial anisotropy revealed by variations up to 8% in the Mg–O and Ga–O bond lengths, which results in variations up to 3% in the Yb–Yb distances along its triangular lattice. Thus, the Yb lattice was not perfectly triangular. Furthermore, we demonstrate an out-of-plane magnetization at the Yb atoms with magnetic anisotropy energy of eV/Yb and a small interlayer exchange of eV/Yb, demonstrating that the system is only approximately two-dimensional. The presented results provide insights for an atomic-scale understanding of YbMgGaO4 with density-functional-theory calculations.