Singlet-triplet excitations and high-field magnetization in CuTe2O5
| Autor: | Wang, Zhe, Schmidt, M., Goncharov, Y., Skourski, Y., Wosnitza, J., Berger, H., von Nidda, H. -A. Krug, Loidl, A., Deisenhofer, J. |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | J. Phys. Soc. Jpn. 80 (2011) 124707 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1143/JPSJ.80.124707 |
| Popis: | By measuring the THz electron spin resonance (ESR) transmission spectra and high-field magnetization on the spin-gapped system CuTe$_2$O$_5$, we identified the singlet-triplet excitations in the dimerized non-magnetic ground state. The determined spin-gap value of $h\nu_0=4.94$ meV at the $\Gamma$ point ($\mathbf{Q}\simeq\mathbf{0}$) is significantly smaller than the strongest antiferromagnetic exchange interaction between the Cu ions predicted by theoretical investigations. We also observed the critical field $H_{c1}^{a^*}=37.6$ T for \textbf{H} $\bot$ \emph{bc}-plane and $H_{c1}^{bc}=40.6$ T for \textbf{H} $\|$ \emph{bc}-plane at the onset of non-zero magnetization, consistent with the gap value and corresponding anisotropic \emph{g}-factors determined previously. The observed singlet-triplet excitations in Faraday and Voigt configurations suggest a mixing of the singlet state with the $S_z=0$ triplet state and the $S_z=\pm 1$ triplet states, respectively, due to the Dzyaloshinskii-Moriya (DM) interaction with a DM vector perpendicular to the crystalline \emph{bc}-plane. Comment: 5 pages, 4 figures |
| Databáze: | arXiv |
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