Magnetic ordering induced by interladder coupling in the spin-1/2 Heisenberg two-leg ladder antiferromagnet C${}_9$H${}_{18}$N${}_2$CuBr${}_4$

Abstract

We present specific-heat and neutron-scattering results for the \emph{S}=1/2 quantum antiferromagnet (dimethylammonium)(3,5-dimethylpyridinium)CuBr${}_4$. The material orders magnetically at \emph{T}${}_N$=1.99(2)\,K, and magnetic excitations are accompanied by an energy gap of 0.30(2) meV due to spin anisotropy. The system is best described as coupled two-leg spin-1/2 ladders with the leg exchange $J_{\mathrm{leg}}$=0.60(2)~meV, rung exchange $J_{\mathrm{rung}}$=0.64(9)~meV, interladder exchange $J_{\mathrm{int}}$=0.19(2)~meV, and an interaction-anisotropy parameter $\lambda$=0.93(2), according to inelastic neutron-scattering measurements. In contrast to most spin ladders reported to date, the material is a rare example in which the interladder coupling is very near the critical value required to drive the system to a Néel-ordered phase without an assistance of a magnetic field.

6 pages, 4 figures

References in corpus (6)

• One- and Two-Triplon Spectra of a Cuprate Ladder
• Direct Observation of Magnon Fractionalization in the Quantum Spin Ladder
• Field-induced Tomonaga-Luttinger liquid phase of a two-leg spin-1/2 ladder with strong leg interactions
• Field-Controlled Magnetic Order in the Quantum Spin-Ladder System (Hpip)2CuBr4
• Neutron scattering evidence for isolated spin-1/2 ladders in (C${}_5$D${}_{12}$N)${}_2$CuBr${}_4$
• Neutron scattering from a coordination polymer quantum paramagnet

Cited by in corpus (6)

• Direct observation of the Higgs amplitude mode in a two-dimensional quantum antiferromagnet near the quantum critical point
• Theoretical study of the spin and charge dynamics of two-leg ladders as probed by resonant inelastic x-ray scattering
• Evidence for pressure induced unconventional quantum criticality in the coupled spin ladder antiferromagnet C${}_9$H${}_{18}$N${}_2$CuBr${}_4$
• The Higgs Mode of Planar Coupled Spin-Ladders and its Observation in C${}_9$H${}_{18}$N${}_2$CuBr${}_4$
• Quantum phases of the biased two-chain-coupled Bose-Hubbard Ladder
• Ising spin ladders of orthopyroxene CoGeO${}_3$