The spin-$\frac{1}{2}$ XXZ chain system Cs$_2$CoCl$_4$ in a transverse magnetic field
| Autor: | Breunig, O., Garst, M., Sela, E., Buldmann, B., Becker, P., Bohatý, L., Müller, R., Lorenz, T. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 111, 187202 (2013) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.111.187202 |
| Popis: | Comparing high-resolution specific heat and thermal expansion measurements to exact finite-size diagonalization, we demonstrate that Cs$_2$CoCl$_4$ for a magnetic field along the crystallographic b axis realizes the spin-$\frac{1}{2}$ XXZ chain in a transverse field. Exploiting both thermal as well as virtual excitations of higher crystal field states, we find that the spin chain is in the XY-limit with an anisotropy $J_z/J_\perp \approx 0.12$ substantially smaller than previously believed. A spin-flop Ising quantum phase transition occurs at a critical field of $\mu_0 H_b^{\rm cr} \approx 2$ T before around 3.5 T the description in terms of an effective spin-$\frac{1}{2}$ chain becomes inapplicable. Comment: 5 pages, 3 figures |
| Databáze: | arXiv |
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