Spin-$\frac{1}{2}$ Heisenberg antiferromagnet on the kagome lattice: ${Z}_{2}$ spin liquid with fermionic spinons

Spin- $\frac{1}{2}$ Heisenberg antiferromagnet on the kagome lattice: $Z_{2}$ spin liquid with fermionic spinons

Zhihao Hao and Oleg Tchernyshyov

Phys. Rev. B 87, 214404 – Published 5 June 2013

Abstract

Motivated by recent numerical and experimental studies of the spin- $1 / 2$ Heisenberg antiferromagnet on the kagome lattice, we formulate a many-body model for fermionic spinons introduced by us earlier [Phys. Rev. Lett. 103, 187203 (2009)]. The spinons interact with an emergent $U (1)$ gauge field and experience strong short-range attraction in the $S = 0$ channel. The ground state of the model is generically a $Z_{2}$ liquid. We calculate the edge of the two-spinon continuum and compare the theory to the slave-fermion approach to the Heisenberg model.