Possible ferro-spin nematic order in NiGa2S4

TL;DR

This paper investigates the potential existence of a ferro-nematic ground state in NiGa2S4, characterized by uniform quadrupole moments without magnetic order, and discusses experimental verification methods.

Contribution

It proposes a new ferro-nematic ground state stabilized by biquadratic interactions in NiGa2S4, contrasting it with previously suggested non-collinear nematic states.

Findings

Ferro-nematic state may exist in NiGa2S4

Physical properties of this state are described

Experimental tests are suggested

Abstract

We explore the possibility that the spin-1 triangular lattice magnet NiGa2 S4 may have a ferro-nematic ground state with no frozen magnetic moment but a uniform quadrupole moment. Such a state may be stabilized by biquadratic spin interactions. We describe the physical properties of this state and suggest experiments to help verify this proposal. We also contrast this state with a `non-collinear' nematic state proposed earlier by Tsunetsugu and Arikawa for NiGa2S4 .