Symmetry and light coupling to phononic and collective magnetic excitations in SrCu_2(BO_3)_2

Abstract

We perform a low temperature Raman scattering study of phononic and collective spin excitations in the orthogonal dimers compound SrCu_2(BO_3)_2, focussing on the symmetry and the effects of external fields on the magnetic modes. The zero field symmetry and the behavior in magnetic fields of the elementary and bound magnetic triplet states are experimentally determined. We find that a minimal 4-spin cluster forming the unit cell is able to describe the symmetry as well as the anisotropic dispersions in external fields of the spin gap multiplet branches around 24 cm^{-1}. We identify two Raman coupling mechanisms responsible for the distinct resonance behavior of these magnetic modes and we show that one of these can be ascribed to an effective intra-dimer Dzyaloshinskii-Moriya spin interaction. Our data also suggest a possible explanation for the existence of a strongly bound two-triplet state in the singlet sector which has an energy below the spin gap. The low temperature phononic spectra suggest strong spin-phonon coupling and show intriguing quasi-degeneracy of modes in the context of the present crystal structure determination.

arXiv comment10 pages, 7 figures

References in corpus (14)

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• Direct Evidence for the Localized Single-Triplet Excitations and the Dispersive Multi-Triplets Excitations in SrCu2(BO3)2
• Dispersion and Symmetry of Bound States in the Shastry-Sutherland Model
• Direct observation of the multiple spin gap excitations in two-dimensional dimer system SrCu2(BO3)2
• Dzyaloshinski-Moriya Interaction in the 2D Spin Gap System SrCu2(BO3)2
• Collective Singlet Excitations and Evolution of Raman Spectral Weights in the 2D Spin Dimer Compound SrCu2(BO3)2
• ESR study on the excited state energy spectrum of SrCu${}_2$(BO${}_3$)${}_2$ -a central role of multiple-triplet bound states
• Dynamic Structure Factor of the Two-Dimensional Shastry-Sutherland Model
• Far infrared study of the two dimensional dimer spin system SrCu_2(BO_3)_2
• Structural Phase Transition in the 2D Spin Dimer Compound SrCu2(BO3)2
• Numerical Calculations of the B1g Raman Spectrum of the Two-Dimensional Heisenberg Model
• $SrC{u}_2(B{O}_3{)}_2$: A Unique Mott Hubbard Insulator
• Far-infrared spectroscopy of spin excitations and Dzyaloshinskii-Moriya interactions in a Shastry-Sutherland compound SrCu${}_2$(BO${}_3$)$_2

Cited by in corpus (13)

• Hall effect of triplons in a dimerized quantum magnet
• Topological Triplon Modes and Bound States in a Shastry-Sutherland Magnet
• Thermodynamic properties of the Shastry-Sutherland model throughout the dimer-product phase
• The effect of Dzyaloshinskii-Moriya interactions on the phase diagram and magnetic excitations of SrCu2(BO3)2
• Thermodynamic properties of highly frustrated quantum spin ladders: influence of many-particle bound states
• Investigation of the oxohalogenide Cu4Te5O12Cl4 with weakly coupled Cu(II) tetrahedra
• Sign-switching of dimer correlations in SrCu${}_2$(BO${}_3$)${}_2$ under hydrostatic pressure
• Magnon Dispersion and Anisotropies in SrCu${}_2$(BO${}_3$)${}_2$
• Raman scattering in a Heisenberg S=1/2 antiferromagnet on the anisotropic triangular lattice
• Ultrafast Frustration-Breaking and Magnetophononic Driving of Singlet Excitations in a Quantum Magnet
• Thermally populated versus field-induced triplon bound states in the Shastry-Sutherland lattice SrCu${}_2$(BO${}_3$)${}_2$
• Theory of the Raman spectra of the Shastry-Sutherland antiferromagnet SrCu${}_2$(BO${}_3$)${}_2$ doped with nonmagnetic impurities
• Triplons, triplon pairs and dynamical symmetries in laser-driven Shastry-Sutherland magnets