Magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet Cs$_2$CuBr$_4$
| Autor: | Zvyagin, S. A., Ozerov, M., Kamenskyi, D., Wosnitza, J., Krzystek, J., Yoshizawa, D., Hagiwara, M., Hu, Rongwei, Ryu, Hyejin, Petrovic, C., Zhitomirsky, M. E. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | New J. Phys. 17, 113059 (2015) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1367-2630/17/11/113059 |
| Popis: | We report on high-field electron spin resonance (ESR) studies of magnetic excitations in the spin-1/2 triangular-lattice antiferromagnet Cs$_2$CuBr$_4$. Frequency-field diagrams of ESR excitations are measured for different orientations of magnetic fields up to 25 T. We show that the substantial zero-field energy gap, $\Delta\approx9.5$ K, observed in the low-temperature excitation spectrum of Cs$_2$CuBr$_4$ [Zvyagin $et~al.$, Phys. Rev. Lett. 112, 077206 (2014)], is present well above $T_N$. Noticeably, the transition into the long-range magnetically ordered phase does not significantly affect the size of the gap, suggesting that even below $T_N$ the high-energy spin dynamics in Cs$_2$CuBr$_4$ is determined by short-range-order spin correlations. The experimental data are compared with results of model spin-wave-theory calculations for spin-1/2 triangle-lattice antiferromagnet. Comment: 6 pages, 9 figures |
| Databáze: | arXiv |
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