The tunable quantum spin ladder Cu(Qnx)(Cl$_{(1-x)}$Br$_{x}$)$_{2}$
| Autor: | Povarov, K. Yu., Lorenz, W. E. A., Xiao, F., Landee, C. P., Krasnikova, Y., Zheludev, A. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | J. Magn. Magn. Mater. 370, 62 (2014) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1016/j.jmmm.2014.06.060 |
| Popis: | We report magnetic, specific heat and ESR measurements on a series of $S=1/2$ spin ladder compounds Cu(Qnx)(Cl$_{(1-x)}$Br$_{x}$)$_{2}$. Down to $T=2$ K all the observables can be described by the spin ladder model with about 1% of $S=1/2$ impurities in the background, which are present even in a nominally pure Cu(Qnx)Cl$_{2}$ and Cu(Qnx)Br$_{2}$, for the whole range of $0\leq x\leq1$. We extract ladder exchange constants $J_{l}(x)$ and $J_{r}(x)$ as well as the gap value $\Delta(x)$ by comparing the experimental data to quantum Monte-Carlo simulations. As the ESR measurements show the $g$-factor of impurities to be precisely equal to $g$-factor of the ladder spins, we suppose the impurities to be the consequence of structural defects resulting in a broken ladder ends. Comment: 8 pages, 7 figures |
| Databáze: | arXiv |
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