Weak-field induced nonmagnetic state in a Co-based honeycomb

TL;DR

This study investigates BaCo2(AsO4)2, revealing that a low magnetic field can suppress magnetic order and induce a nonmagnetic state, highlighting magnetic frustration and weak non-Kitaev interactions in a 3d honeycomb magnet.

Contribution

It demonstrates the suppression of magnetic order in a 3d honeycomb magnet using a low magnetic field, providing insights into Kitaev physics in weak spin-orbit coupling materials.

Findings

Magnetic order is fully suppressed by a low magnetic field.

The material becomes non-magnetic under applied field.

Weak non-Kitaev interactions are inferred from the results.

Abstract

Layered honeycomb magnets are of interest as potential realizations of the Kitaev quantum spin liquid (KQSL), a quantum state with long-range spin entanglement and an exactly solvable Hamiltonian. Conventional magnetically ordered states are present for all currently known candidate materials, however, because non-Kitaev terms in the Hamiltonians obscure the Kitaev physics. Current experimental studies of the KQSL are focused on 4d- or 5d-transition-metal-based honeycombs, in which strong spin-orbit coupling can be expected, yielding Kitaev interaction that dominate in an applied magnetic field. In contrast, for 3d-based layered honeycomb magnets, spin orbit coupling is weak and thus Kitaev-physics should be substantially less accessible. Here we report our studies on BaCo2(AsO4)2, for which we find that the magnetic order associated with the non-Kitaev interactions can be fully suppressed by a relatively low magnetic field, yielding a non-magnetic material and implying the presence of strong magnetic frustration and weak non-Kitaev interactions.