Dispersive magnetic excitations in the S=1 antiferromagnet Ba${}_3$Mn${}_2$O${}_8$

Abstract

We present powder inelastic neutron scattering measurements of the S=1 dimerized antiferromagnet Ba${}_3$Mn${}_2$O${}_8$. The $T=1.4$ K magnetic spectrum exhibits a spin-gap of $\Delta \approx 1.0$ meV and a dispersive spectrum with a bandwidth of approximately 1.5 meV. Comparison to coupled dimer models describe the dispersion and scattering intensity accurately and determine the exchange constants in Ba${}_3$Mn${}_2$O${}_8$. The wave vector dependent scattering intensity confirms the proposed S=1 dimer bond. Temperature dependent measurements of the magnetic excitations indicate the presence of both singlet-triplet and thermally activated triplet-quintet excitations.

8 pages, 8 figures, Submitted to Physical Review B, Resubmited version

References in corpus (5)

• Dimensional reduction at a quantum critical point
• Field Induced Supersolid Phase in Spin-One Heisenberg Models
• Spin Supersolid in Anisotropic Spin-One Heisenberg Chain
• Field-driven phase transitions in a quasi-two-dimensional quantum antiferromagnet
• Neutron scattering from a coordination polymer quantum paramagnet

Cited by in corpus (7)

• Singlet-triplet dispersion reveals additional frustration in the triangular dimer compound Ba${}_3$Mn${}_2$O${}_8$
• Asymmetric quintuplet condensation in the frustrated S=1 spin dimer compound Ba3Mn2O8
• Ordered magnetic phases of the frustrated spin-dimer compound Ba3Mn2O8
• Non-linear bond-operator theory and 1/d expansion for coupled-dimer magnets I: Paramagnetic phase
• Weakly coupled alternating $S=1/2$ chains in the distorted honeycomb lattice compound Na${}_2$Cu${}_2$TeO${}_6$
• Infrared phonons and specific heat in Ba3Cr2O8
• Dynamics of the two-dimensional S=1/2 dimer system (C5H6N2F)2CuCl4