Quasi-one-dimensional exchange interactions and short-range magnetic correlations in CuTeO 4
Not provided.
Materials Science↗
Engineering topics
Halloran, Thomas
Publications and source records attributed to Halloran, Thomas.
Noncollinear 2 k antiferromagnetism in the Zintl semiconductor Eu 5 In 2 Sb 6
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Morano, Vincent C. (ORCID:0009000216490887)↗
Chemical tuning of a honeycomb magnet through a critical point
BaCo 2 (AsO 4 ) 2 (BCAO) has seen extensive study since its initial identification as a proximate Kitaev quantum spin liquid candidate. Thought to be described by the highly anisotropic XXZ-J 1 -J 3 model, the ease with which magnetic order is suppressed in the system indicates proximity to a spin liquid phase. Upon chemical tuning via partial arsenic substitution with vanadium, we show an initial suppression of long-range incommensurate order in the BCAO system to T ≈ 3.0 K, followed by increased spin freezing at higher substitution levels. Between these two regions, at around 10% substitution, the system is shown to pass through a critical point where the competing J 1 /J 3 exchange interactions become more balanced, producing a more complex magnetic ground state, likely stabilized by quantum fluctuations. Here, this state shows how slight compositional change in magnetically frustrated systems may be leveraged to tune ground state degeneracies and potentially realize a quantum spin liquid state.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
Geometrical frustration versus Kitaev interactions in BaCo 2 (AsO 4 ) 2
Recently, Co-based honeycomb magnets have been proposed as promising candidate materials to host the Kitaev spin liquid (KSL) state. One of the front-runners is BaCo 2 (AsO 4 ) 2 (BCAO), where it was suggested that the exchange processes between Co 2+ ions via the surrounding edge-sharing oxygen octahedra could give rise to bond-dependent Kitaev interactions. In this work, we present and analyze a comprehensive inelastic neutron scattering (INS) study of BCAO with fields in the honeycomb plane. Combining the constraints from the magnon excitations in the high-field polarized state and the inelastic spin structure factor measured in zero magnetic field, we examine two leading theoretical models: the Kitaev-type JK Γ Γ ′ model and the XXZ - J 1 - J 3 model. We show that the existing experimental data can be consistently accounted for by the XXZ - J 1 - J 3 model but not by the JK Γ Γ ′ model, and we discuss the implications of these results for the realization of a spin liquid phase in BCAO and more generally for the realization of the Kitaev model in cobaltates.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Magnetic excitations and interactions in the Kitaev hyperhoneycomb iridate β –Li 2 IrO 3
Here, we present a thorough experimental study of the three-dimensional hyperhoneycomb Kitaev magnet β –Li 2 IrO 3 , using a combination of inelastic neutron scattering (INS), time-domain terahertz spectroscopy (TDTS), and heat capacity measurements. The main results include a massive low-temperature reorganization of the INS spectral weight that evolves into a broad peak centered around 12 meV, and a distinctive peak in the terahertz data at 2.8(1) meV. A detailed comparison to powder-averaged spin-wave theory calculations reveals that the positions of these two features are controlled by the anisotropic Γ coupling and the Heisenberg exchange J, respectively. The refined microscopic spin model places β –Li 2 IrO 3 in close proximity to the Kitaev spin liquid phase.
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗