Scaling relation of the Dirac-like spinons in the S=1/2 Kagome antiferromagnet YCu3[OD]6.5Br2.5

An S=1/2 Kagome Heisenberg antiferromagnet (KHA) is proposed for a paradigmatic setting for achieving quantum spin liquids (QSLs). To date, a number of S=1/2 KHA have been reported to be QSL candidates, featuring fractionalized spin excitations and the absence of long-range order. Nevertheless, the Zn-Cu intersite disorders disallow identifying a ground state inherent to KHAs and hindering the observation of the predicted 1/9 plateau. Rather, lattice imperfections and magnetic defects bring about the coexistence of gapped singlets and gapless states and conceal the intrinsic low-E excitations. The recently discovered YCu3[OD]6.5Br2.5 (YCODB) has been considered as the most promising Kagome QSL candidate. This is because YCODB is free from the site mixing of the magnetic Cu2+ ions. YCODB shows no magnetic ordering or freezing down to 50 mK and exhibits a nearly quadratic T dependence of specific heat, reminiscent of a Dirac-like QSL. Singularly, the highly sought-after 1/9 magnetization plateau has been observed for the first time in this compound, highlighting its importance in the research of kagome physics. In this project, we aim to investigate the scaling relation of the Dirac-like spinons against magnetic fields in the S=1/2 KHA YCODB.