Fermionic spin excitations in two and three-dimensional antiferromagnets

Abstract

Spin excitations in an ordered Heisenberg magnet are magnons--bosons with spin 1. That may change when frustration and quantum fluctuations suppress the order and restore the spin-rotation symmetry. We show that spin excitations in the $S=1/2$ Heisenberg antiferromagnet on kagome are spinons--fermions with spin 1/2. In the ground state the system can be described as a collection of small, heavy pairs of spinons with spin 0. A magnetic excitation of lowest energy amounts to breaking up a pair into two spinons at a cost of $0.06J$.

4 pages, 4 figures, accepted version of the manuscript

References in corpus (6)

• Bose-Einstein Condensation in Magnetic Insulators
• Properties of an algebraic spin liquid on the kagome lattice
• Ground State of the Kagome Lattice Heisenberg Antiferromagnet
• Electronic Orbital Currents and Polarization in Mott Insulators
• Triplet and Singlet Excitations in the Valence Bond Crystal Phase of Kagome Lattice Heisenberg Model
• Quantum kagome antiferromagnet in a magnetic field: Low-lying non-magnetic excitations versus valence-bond crystal order