Longitudinal magnon in the tetrahedral spin system Cu2Te2O5Br2 near quantum criticality

Abstract

We present a comprehensive study of the coupled tetrahedra-compound Cu2Te2O5Br2 by theory and experiments in external magnetic fields. We report the observation of a longitudinal magnon in Raman scattering in the ordered state close to quantum criticality. We show that the excited tetrahedral-singlet sets the energy scale for the magnetic ordering temperature T_N. This energy is determined experimentally. The ordering temperature T_N has an inverse-log dependence on the coupling parameters near quantum criticality.

References in corpus (10)

• Dynamics of coupled quantum spin chains
• Magnetic light scattering in low-dimensional quantum spin systems
• A Novel Longitudinal Mode in the Coupled Quantum Chain Compound KCuF3
• Evidence for an unconventional magnetic instability in the spin-tetrahedra system Cu_2Te_2O_5Br_2
• Magnetic properties and spin waves of bilayer magnets in a uniform field
• Magnetism of a tetrahedral cluster spin-chain
• Polarized-neutron study of longitudinal Haldane-gap excitations in Nd${}_2$BaNiO${}_5$
• Dynamical Properties of an Antiferromagnet near the Quantum Critical Point: Application to LaCuO_2.5
• Low-lying excitations and magnetization process of coupled tetrahedral systems
• Low Energy Singlets in the Excitation Spectrum of the Spin Tetrahedra System Cu_2Te_2O_5Br_2

Cited by in corpus (32)

• Neutron Scattering and Magnetic Observables for S = 1/2 Molecular Magnets
• Structural and magnetic dimers in the spin-gapped system CuTe2O5
• Longitudinal Magnetic Dynamics and Dimensional Crossover in the Quasi-One-Dimensional, Spin-1/2, Heisenberg Antiferromagnet KCuF3
• Tetrahedra system Cudaca: high-temperature manifold of molecular configurations governing low-temperature properties
• Investigation of the oxohalogenide Cu4Te5O12Cl4 with weakly coupled Cu(II) tetrahedra
• Halogen-mediated exchange in the coupled-tetrahedra quantum spin systems Cu2Te2O5X2 (X=Br,Cl)
• Incommensurate magnetic ordering in $C{u}_{2}T{e}_2{O}_5{X}_2$ (X=Cl,Br) studied by neutron diffraction
• Incommensurate magnetic ordering in Cu2Te2O5X2 (X=Cl, Br) studied by single crystal neutron diffraction
• Magnetic Raman scattering of the ordered tetrahedral spin-1/2 clusters in Cu_2Te_2O_5(Br_(1-x)Cl_x)_2 compounds
• Ground state order and spin-lattice coupling in tetrahedral spin systems Cu2Te2O5X2
• Weak antiferromagnetism and dimer order in quantum systems of coupled tetrahedra
• Spin gap formation in the quantum spin systems TiOX, X=Cl and Br
• Proposed low energy model Hamiltonian for spin-gapped system CuTe2O5
• New Method to Calculate the Sign and Relative Strength of Magnetic Interactions in Low-Dimensional Systems on the Basis of Structural Data
• Neutron inelastic scattering investigation of the magnetic excitations in Cu_2Te_2O_5X_2 (X=Br, Cl)
• Magnetic excitations and phonons in the spin-chain compound NaCu2O2
• Anomalous frequency and intensity scaling of collective and local modes in a coupled spin tetrahedron system
• Unusual criticality of Cu2Te2O5Br2 under pressure
• Frustrated antiferromagnetic spin chains of edge-sharing tetrahedra in volcanic minerals K3Cu3(Fe0.82Al0.18)O2(SO4)4 and K4Cu4O2(SO4)4MeCl
• Persistence of singlet fluctuations in the coupled spin tetrahedra system Cu2Te2O5Br2 revealed by high-field magnetization and 79Br NQR - 125Te NMR
• Dynamical lattice instability versus spin liquid state in a frustrated spin chain system
• Simultaneous Charge Ordering and Spin Dimerization in Quasi-Two-Dimensional Quarter-Filled Ladders
• NMR and NQR study of the tetrahedral frustrated quantum spin system Cu2Te2O5Br2 in its paramagnetic phase
• Series expansion analysis of a tetrahedral cluster spin chain
• The effect of externally applied pressure on the magnetic behavior of Cu2Te2O5(BrxCl{1-x})2
• Anisotropic field dependence of the magnetic transition in Cu2Te2O5Br2
• Raman study of spin excitations in the tunable quantum spin ladder Cu(Qnx)(Cl${}_{1-x}$Br${}_x$)${}_2$
• Microscopic model for the novel frustrated Cu(II)-spin tetrahedron-based Cu4Te5O12X4 (X=Cl, Br) systems
• Longitudinal Excitations in Bipartite and Hexagonal Antiferromagnetic Spin Lattices
• Dynamic spin Jahn-Teller effect in small magnetic clusters
• Incommensurate magnetism in the coupled spin tetrahedra system Cu2Te2O5Cl2
• Comparative investigation of the coupled-tetrahedra quantum spin systems Cu2Te2O5X2, X=Cl, Br and Cu4Te5O12Cl4