Magnetic ordering induced by interladder coupling in the spin-1/2 Heisenberg two-leg ladder antiferromagnet C$_9$H$_{18}$N$_2$CuBr$_4$
| Autor: | Hong, Tao, Schmidt, K. P., Coester, K., Awwadi, F. F., Turnbull, M. M., Qiu, Y., Rodriguez-Rivera, J. A., Zhu, M., Ke, X., Aoyama, C. P., Takano, Y., Cao, Huibo, Tian, W., Ma, J., Custelcean, R., Zhou, H. D., Matsuda, M. |
|---|---|
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Physical Review B 89, 174432 (2014) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.89.174432 |
| Popis: | 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 $J_{\rm leg}$=0.60(2)~meV, rung exchange $J_{\rm rung}$=0.64(9)~meV, interladder exchange $J_{\rm int}$=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 N\'eel-ordered phase without an assistance of a magnetic field. Comment: 6 pages, 4 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|