Experimental Evidence for the Spiral Spin Liquid in LiYbO$_2$

TL;DR

This study provides experimental evidence that LiYbO$_2$ hosts a spiral spin liquid, a rare magnetic state characterized by fluctuating spin spirals, confirmed through neutron scattering techniques.

Contribution

The paper demonstrates that LiYbO$_2$ is the first material experimentally shown to realize a spiral spin liquid predicted by the $J_1$-$J_2$ Heisenberg model on an elongated diamond lattice.

Findings

LiYbO$_2$ exhibits continuous spiral spin contours in neutron scattering data.

LiYbO$_2$ fulfills the conditions for a spiral spin liquid according to experimental evidence.

Reconstruction of diffuse neutron scattering maps confirms the presence of spiral spin liquid features.

Abstract

Spiral spin liquids are an exotic class of correlated paramagnets with an enigmatic magnetic ground state composed of a degenerate manifold of fluctuating spin spirals. Experimental realisations of the spiral spin liquid are scarce, mainly due to the prominence of structural distortions in candidate materials that can trigger order-by-disorder transitions to more conventionally ordered magnetic ground states. Expanding the pool of candidate materials that may host a spiral spin liquid is therefore crucial to realising this novel magnetic ground state and understanding its robustness against perturbations that arise in real materials. Here, we show that the material LiYbO$_2$ is the first experimental realisation of a spiral spin liquid predicted to emerge from the $J_1$-$J_2$ Heisenberg model on an elongated diamond lattice. Through a complementary combination of high-resolution and diffuse neutron magnetic scattering studies on a polycrystalline sample, we demonstrate that LiYbO$_2$ fulfils the requirements for the experimental realisation of the spiral spin liquid and reconstruct single-crystal diffuse neutron magnetic scattering maps that reveal continuous spiral spin contours -- a characteristic experimental hallmark of this exotic magnetic phase.