Evidence of a bond-nematic phase in LiCuVO4

TL;DR

This study provides experimental evidence for a bond-nematic phase in LiCuVO4, characterized by quadrupolar fluctuations and short-range dipolar correlations, revealed through neutron scattering and heat capacity measurements.

Contribution

First experimental identification of a bond-nematic phase in LiCuVO4 driven by quadrupolar fluctuations at high magnetic fields.

Findings

Phase transition at 8 Tesla driven by quadrupolar fluctuations

Short-range dipolar correlations with moments parallel to magnetic field

Evidence of bond-nematic order with fluid-like interchain coherence

Abstract

Polarized and unpolarized neutron scattering experiments on the frustrated ferromagnetic spin-1/2 chain LiCuVO4 show that the phase transition at HQ of 8 Tesla is driven by quadrupolar fluctuations and that dipolar correlations are short-range with moments parallel to the applied magnetic field in the high-field phase. Heat-capacity measurements evidence a phase transition into this high-field phase, with an anomaly clearly different from that at low magnetic fields. Our experimental data are consistent with a picture where the ground state above HQ has a next-nearest neighbour bond-nematic order along the chains with a fluid-like coherence between weakly coupled chains.