Spatial anisotropy of the quantum spin liquid system YbMgGaO4 revealed by ab initio calculations

Author(s)

Lima, Matheus P.

• Document type: Journal article
• Source: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 32, n. 2 JAN 9 2020.
• Web of Science Citations: 0

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 1.7 x 10(-4) eV/Yb and a small interlayer exchange of 8.7 x 10(-5) 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. (AU)

• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants