Fractionalized excitations in the spin liquid state of a kagom\'{e} lattice antiferromagnet

TL;DR

This paper reports neutron scattering evidence of a spinon continuum in herbertsmithite, providing strong evidence for a quantum spin liquid state in a two-dimensional kagome lattice antiferromagnet, which is significant for understanding exotic magnetic states.

Contribution

First observation of a spinon continuum in a 2D kagome lattice antiferromagnet, confirming the quantum spin liquid state in herbertsmithite.

Findings

Detection of a spinon continuum in neutron scattering data

Evidence supporting the quantum spin liquid state in herbertsmithite

Implications for topological quantum states and high-Tc superconductivity

Abstract

New physics can emerge in magnetic materials where quantum fluctuations are enhanced due to reduced dimensionality and strong frustration. One long sought example is the resonating-valence-bond (RVB) state, where atomic magnetic moments are strongly correlated but do not order or freeze even in the limit of T -> 0. The RVB ground state does not break conventional symmetries, such as lattice translation or spin-rotation. The realization of such a quantum spin liquid in two-dimensions would represent a new state of matter. It is believed that spin liquid physics plays a role in the phenomenon of high-Tc superconductivity, and the topological properties of the spin liquid state may have applications in the field of quantum information. We present neutron scattering measurements of the spin excitations on single crystal samples of the spin-1/2 kagom\'{e} lattice antiferromagnet ZnCu3(OD)6Cl2 (also called herbertsmithite). Our observation of a spinon continuum in a two-dimensional magnet is remarkable first. The results serve as a key fingerprint of the quantum spin liquid state in herbertsmithite.