Experimental Realization of Spin-1/2 Triangular-Lattice Heisenberg Antiferromagnet

TL;DR

This paper reports the experimental realization of a spin-1/2 Heisenberg antiferromagnet on a triangular lattice using Ba3CoSb2O9, with measurements aligning well with theoretical predictions, including the one-third magnetization plateau.

Contribution

It demonstrates that Ba3CoSb2O9 is a physical realization of the spin-1/2 triangular-lattice Heisenberg antiferromagnet, confirming theoretical models through experimental data.

Findings

Magnetization and specific heat measurements support the realization.

Magnetization curve matches theoretical calculations.

Observation of the one-third quantum magnetization plateau.

Abstract

We report the results of magnetization and specific heat measurements on Ba$_3$CoSb$_2$O$_9$, in which the magnetic Co$^{2+}$ ion has a fictitious spin-1/2, and show evidence that a spin-1/2 Heisenberg antiferromagnet on a regular triangular lattice is actually realized in Ba$_3$CoSb$_2$O$_9$. We found that the entire magnetization curve including the one-third quantum magnetization plateau is in excellent agreement with theoretical calculations at a quantitative level.