Origin of magnetic anisotropy in the spin ladder compound (C${}_5$H${}_{12}$N)${}_2$CuBr${}_4$

Abstract

The $S=1/2$ spin ladder compound (C${}_5$H${}_{12}$N)${}_2$CuBr${}_4$ (BPCB) is studied by means of high-resolution inelastic neutron scattering. In agreement with previous studies we find a band of triplet excitations with a spin gap of $\sim 0.8$~meV and a bandwidth of $\sim 0.6$~meV. In addition, we observe a distinct splitting of the triplet band of $50(1)$~$\mu$eV or $40(2)$~$\mu$eV at the band minimum or maximum, respectively. By comparison to a strong coupling expansion calculation of the triplet dispersion for a spin ladder with anisotropic exchange, weakly anisotropic leg interactions are identified as the dominant source of magnetic anisotropy in BPCB. Based on these results, we discuss the nature of magnetic exchange anisotropy in BPCB and in related transition-metal insulators.

References in corpus (16)

• Theory of the field-induced gap in $S=1/2$ antiferromagnetic chains
• On the Field-Induced Gap in Cu Benzoate and Other S=1/2 Antiferromagnets
• Direct Measurement of the Spin Hamiltonian and Observation of Condensation of Magnons in the 2D Frustrated Quantum Magnet Cs2CuCl4
• Controlling Luttinger liquid physics in spin ladders under a magnetic field
• Thermodynamics of the Spin Luttinger-Liquid in a Model Ladder Material
• Direct Observation of Magnon Fractionalization in the Quantum Spin Ladder
• Excitation hierarchy of the quantum sine-Gordon spin chain in strong magnetic field
• Strong Coupling Expansions for Antiferromagnetic Heisenberg S=1/2 Ladders
• Experimental evidence for Shekhtman-Entin-Wohlman-Aharony (SEA) interactions in Ba2CuGe2O7
• Magnetic order and spin-waves in the quasi-1D S=1/2 antiferromagnet $\mathbf{BaC}{\mathbf{u}}_2\mathbf{S}{\mathbf{i}}_2{\mathbf{O}}_7$
• Quantum spin chains with frustration due to Dzyaloshinskii-Moriya interactions
• Neutron scattering evidence for isolated spin-1/2 ladders in (C${}_5$D${}_{12}$N)${}_2$CuBr${}_4$
• Anisotropy of Magnetic Interactions in the Spin-Ladder Compound (C${}_5$H${}_{12}$N)${}_2$CuBr${}_4$
• $z=2$ Quantum Critical Dynamics in a Spin Ladder
• Spin dynamics and exchange interactions in CuO measured by neutron scattering
• Magnetic structure and spin waves in the frustrated ferro-antiferromagnet Pb${}_2$VO(PO${}_4$)${}_2$

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