Strain-tunable magnetic correlations in spin liquid candidate Nb 3 Cl 8

Abstract Recent research suggests the possibility of the two-dimensional breathing-Kagome magnet Nb 3 Cl 8 hosting a quantum spin liquid state, warranting further study into its magnetic properties. Using ab initio calculations, we show that monolayer Nb 3 Cl 8 has short-range antiferromagnetic (AFM) correlations among Nb 3 trimers with S = 1 / 2 , and becomes magnetically frustrated due to the underlying effective triangular lattice geometry, and is evidenced by a frustration index of f > 1. The high-temperature susceptibility shows a negative Weiss temperature from Monte Carlo calculations. Considering spin–orbit coupling, we investigate the magnetic anisotropy, including anisotropic exchange, single-ion anisotropy and the Dzyaloshinskii–Moriya interaction (DMI) using the four-state energy mapping formalism. Although the elements have relatively small atomic numbers, the DMI is comparable in magnitude to the anisotropic exchange. Additionally, we show that biaxial strain tunes the short-range correlations between AFM, paramagnetic and ferromagnetic. These findings strengthen our understanding of Nb 3 Cl 8 and advance its applications in current condensed matter physics and materials science research, including nanoscale mechanical and spintronics applications.