Singlet-triplet excitations and high-field magnetization in CuTe2O5

Abstract

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 ($\mathbf{Q}\simeq 0$) is significantly smaller than the strongest antiferromagnetic exchange interaction between the Cu ions predicted by theoretical investigations. We also observed the critical field $H_{c1}^{a^{\ast }}=37.6$ T for \textbf{H} $\perp$ \emph{bc}-plane and $H_{c1}^{bc}=40.6$ T for \textbf{H} $\Vert$ \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.

5 pages, 4 figures

References in corpus (4)

• Bose-Einstein Condensation in Magnetic Insulators
• Structural and magnetic dimers in the spin-gapped system CuTe2O5
• Weakly coupled $s=1/2$ quantum spin singlets in Ba${}_3$Cr${}_2$O${}_8$
• Proposed low energy model Hamiltonian for spin-gapped system CuTe2O5

Cited by in corpus (8)

• High-field spectroscopy of singlet-triplet transitions in the spin-dimer systems Sr3Cr2O8 and Ba3Cr2O8
• Electron spin resonance and exchange paths in the orthorhombic dimer system Sr2VO4
• Magnetization and specific heat of the dimer system CuTe2O5
• Low-energy magnetic excitations in the quasi-one-dimensional spin-1 chain compound SrNi2V2O8
• Infrared phonons and specific heat in Ba3Cr2O8
• THz spectroscopy in the pseudo-Kagome system Cu3Bi(SeO3)2O2Br
• Low-energy spin excitations in field-induced phases of the spin-ladder antiferromagnet BiCu${}_2$PO${}_6$
• Anomalous magnetic exchange in a dimerized quantum-magnet composed of unlike spin species