Quasi-two-dimensional Bose-Einstein condensation of spin triplets in dimerized quantum magnet Ba${}_2$CuSi${}_2$O${}_6$Cl${}_2$

Abstract

We synthesized single crystals of composition Ba${}_2$CuSi${}_2$O${}_6$Cl${}_2$ and investigated its quantum magnetic properties. The crystal structure is closely related to that of the quasi-two-dimensional (2D) dimerized magnet BaCuSi${}_2$O${}_6$ also known as Han purple. Ba${}_2$CuSi${}_2$O${}_6$Cl${}_2$ has a singlet ground state with an excitation gap of $\Delta /k_{\mathrm{B}}=20.8$ K. The magnetization curves for two different field directions almost perfectly coincide when normalized by the $g$-factor except for a small jump anomaly for a magnetic field perpendicular to the $c$ axis. The magnetization curve with a nonlinear slope above the critical field is in excellent agreement with exact-diagonalization calculations based on a 2D coupled spin-dimer model. Individual exchange constants are also evaluated using density functional theory (DFT). The DFT results demonstrate a 2D exchange network and weak frustration between interdimer exchange interactions, supported by weak spin-lattice coupling implied from our magnetostriction data. The magnetic-field-induced spin ordering in Ba${}_2$CuSi${}_2$O${}_6$Cl${}_2$ is described as the quasi-2D Bose-Einstein condensation of triplets.

arXiv comment9 pages, 7 figures, to appear in Phys. Rev. B

References in corpus (30)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Maximally-localized generalized Wannier functions for composite energy bands
• Wannier90: A Tool for Obtaining Maximally-Localised Wannier Functions
• A linear response approach to the calculation of the effective interaction parameters in the LDA+U method
• Pseudopotentials for high-throughput DFT calculations
• Exciton-polariton condensates
• Bose-Einstein Condensation in Magnetic Insulators
• Realization of Bose-Einstein condensation of dilute magnons in TlCuCl${}_3$
• Density functional theory in transition-metal chemistry: a self-consistent Hubbard U approach
• Quantum magnetism and criticality
• Amplitude / Higgs Modes in Condensed Matter Physics
• Magnetic Field-Induced Condensation of Triplons in Han Purple Pigment BaCuSi${}_2$O${}_6$
• Quantum Magnets under Pressure: Controlling Elementary Excitations in TlCuCl3
• Dimensional reduction at a quantum critical point
• Field- and pressure-induced magnetic quantum phase transitions in TlCuCl_3
• Magnetostriction and magnetic texture to 97.4 Tesla in frustrated SrCu2(BO3)2
• Temperature-dependent spin gap and singlet ground state in BaCuSi2O6
• Field-Induced Magnetic Ordering in the Quantum Spin System KCuCl${}_3$
• Magnetic-Field Induced Bose-Einstein Condensation of Magnons and Critical Behavior in Interacting Spin Dimer System TlCuCl${}_3$
• High resolution magnetostriction measurements in pulsed magnetic fields using Fibre Bragg Gratings
• Experimental evidence for Shekhtman-Entin-Wohlman-Aharony (SEA) interactions in Ba2CuGe2O7
• Multiple Magnon Modes and Consequences for the Bose-Einstein Condensed Phase in BaCuSi2O6
• Neutron Diffraction Study of the Pressure-Induced Magnetic Ordering in the Spin Gap System TlCuCl${}_3$
• Quantum Phase Transitions in Coupled Dimer Compounds
• Magnetic frustration in BaCuSi2O6 released
• Pressure-Induced Magnetic Quantum Phase Transitions from Gapped Ground State in TlCuCl3
• Pressure-Induced Successive Magnetic Phase Transitions in the Spin Gap System TlCuCl${}_3$
• Pressure-Induced Magnetic Quantum Phase Transition in Gapped Spin System KCuCl3
• Almost Perfect Frustration in the Dimer Magnet Ba${}_2$CoSi${}_2$O${}_6$Cl${}_2$
• Low temperature structural phase transition and incommensurate lattice modulation in the spin gap compound BaCuSi2O6

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