Quantum spin liquid in frustrated one dimensional LiCuSbO4

TL;DR

This paper reports the discovery of a quantum spin liquid state in the frustrated one-dimensional magnet LiCuSbO4, characterized by incommensurate correlations and absence of magnetic order down to very low temperatures.

Contribution

It provides experimental evidence of a quantum spin liquid in a one-dimensional frustrated magnet and models the system with exact diagonalization.

Findings

No magnetic phase transition down to 100 mK.

Incommensurate spin correlations with q ≈ 0.47π/a.

Neutron scattering limits on spin gap < 70 μeV.

Abstract

A quantum magnet, LiCuSbO4, with chains of edge-sharing S = 1/2 CuO6 octahedra is reported. While the Curie-Weiss constant is ferromagnetic, \theta = 30 K, no phase transition or spin freezing occurs down to 100 mK. Specific heat indicates a distinct high field phase near the 12 T saturation field. Neutron scattering shows incommensurate spin correlations with q = 0.47\pm0.01{\pi}/a and places an upper limit of 70 \mueV on a potential spin gap. Exact diagonalization of easy plane S = 1/2 chains with competing ferro- and antiferromagnetic interactions (J1 = - 75 K, J2 = 34 K) accounts for the T > 2 K data.