Field-induced bound-state condensation and spin-nematic phase in SrCu${}_2$(BO${}_3$)${}_2$ revealed by neutron scattering up to 25.9 T

Abstract

Bose-Einstein condensation (BEC) underpins exotic forms of order ranging from superconductivity to superfluid 4 He. In quantum magnetic materials, ordered phases induced by an applied magnetic field can be described as the BEC of magnon excitations. With sufficiently strong magnetic frustration, exemplified by the system SrCu${}_2$(BO${}_3$)${}_2$ , no clear magnon BEC is observed and the complex spectrum of multi-magnon bound states may allow a different type of condensation, but the high fields required to probe this physics have remained a barrier to detailed investigation. Here we exploit the first purpose-built high-field neutron scattering facility to measure the spin excitations of SrCu${}_2$(BO${}_3$)${}_2$ up to 25.9 T and use cylinder matrix-product-states (MPS) calculations to reproduce the experimental spectra with high accuracy. Multiple unconventional features point to a condensation of $S=2$ bound states into a spin-nematic phase, including the gradients of the one-magnon branches, the presence of many novel composite two- and three-triplon excitations and the persistence of a one-magnon spin gap. This gap reflects a direct analogy with superconductivity, suggesting that the spin-nematic phase in SrCu${}_2$(BO${}_3$)${}_2$ is best understood as a condensate of bosonic Cooper pairs. Our results underline the wealth of unconventional states yet to be found in frustrated quantum magnetic materials under extreme conditions.

References in corpus (41)

• The density-matrix renormalization group in the age of matrix product states
• Time-dependent variational principle for quantum lattices
• Unifying time evolution and optimization with matrix product states
• Bose-Einstein Condensation in Magnetic Insulators
• Time-evolution methods for matrix-product states
• Realization of Bose-Einstein condensation of dilute magnons in TlCuCl${}_3$
• Studying Two Dimensional Systems With the Density Matrix Renormalization Group
• Magnetic Superstructure in the Two-Dimensional Quantum Antiferromagnet SrCu2(BO3)2
• Nematic order in square lattice frustrated ferromagnets
• Magnetic Field-Induced Condensation of Triplons in Han Purple Pigment BaCuSi${}_2$O${}_6$
• BCS-BEC Crossover and the Unitary Fermi Gas
• Direct Evidence for the Localized Single-Triplet Excitations and the Dispersive Multi-Triplets Excitations in SrCu2(BO3)2
• Tensor network study of the Shastry-Sutherland model in zero magnetic field
• Magnon pairing in quantum spin nematic
• Magnetization of SrCu2(BO3)2 in ultrahigh magnetic fields up to 118 T
• Crystals of bound states in the magnetization plateaus of the Shastry-Sutherland model
• Magnetization plateaus of the Shastry-Sutherland model for SrCu_2(BO_3)_2: SDW, supersolid and bound states
• Observation of a 4-spin Plaquette Singlet State in the Shastry-Sutherland compound SrCu2(BO3)2
• Magnetostriction and magnetic texture to 97.4 Tesla in frustrated SrCu2(BO3)2
• A quantum magnetic analogue to the critical point of water
• Topological Triplon Modes and Bound States in a Shastry-Sutherland Magnet
• Dzyaloshinski-Moriya Interaction in the 2D Spin Gap System SrCu2(BO3)2
• Quantum phases of SrCu2(BO3)2 from high-pressure thermodynamics
• Nuclear magnetic resonance signature of the spin-nematic phase in LiCuVO${}_4$ at high magnetic fields
• Collective Singlet Excitations and Evolution of Raman Spectral Weights in the 2D Spin Dimer Compound SrCu2(BO3)2
• Incomplete devil's staircase in the magnetization curve of SrCu2(BO3)2
• Phase diagram of the Shastry-Sutherland Compound SrCu2(BO3)2 under extreme combined conditions of field and pressure
• High Resolution Study of Spin Excitations in the Shastry-Sutherland Singlet Ground State of 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
• Thermodynamic properties of the Shastry-Sutherland model throughout the dimer-product phase
• Low-Lying Magnetic Excitation of the Shastry-Sutherland Model
• Multiple Magnon Modes and Consequences for the Bose-Einstein Condensed Phase in BaCuSi2O6
• Uniform and staggered magnetizations induced by Dzyaloshinskii-Moriya interactions in isolated and coupled spin 1/2 dimers in a magnetic field
• Dynamics and Instabilities of the Shastry-Sutherland Model
• Unveiling new quantum phases in the Shastry-Sutherland compound SrCu2(BO3)2up to the saturation magnetic field
• Field-Induced Effects of Anisotropic Magnetic Interactions in SrCu2(BO3)2
• Correlated decay of triplet excitations in the Shastry-Sutherland compound SrCu${}_2$(BO${}_3$)${}_2$
• Absence of single particle Bose-Einstein condensation at low densities for bosons with correlated-hopping
• Thermally populated versus field-induced triplon bound states in the Shastry-Sutherland lattice SrCu${}_2$(BO${}_3$)${}_2$
• Magnetic field induced bound states in spin-$\frac{1}{2}$ ladders
• Investigating field-induced magnetic order in Han Purple by neutron scattering up to 25.9 T

Cited by in corpus (9)

• Emergent criticality in fully frustrated quantum magnets
• Possible Observation of Quadrupole Waves in Spin Nematics
• Frustration and chirality in three-dimensional trillium lattices: Insights and Perspectives
• Triplons, triplon pairs and dynamical symmetries in laser-driven Shastry-Sutherland magnets
• Anomalous thermal broadening in the Shastry-Sutherland model and SrCu${}_2($BO${}_3{)}_2$
• Dynamics of quantum spin-nematics: Comparisons with canted antiferromagnets
• Bullet pressure-cell design for neutron scattering experiments with horizontal magnetic fields and dilution temperatures
• Possible Bose-Einstein condensation of magnons in a S = 5/2 honeycomb lattice
• Coupled dimerized alternating-bond quantum spin chains in the distorted honeycomb-lattice magnet Cu${}_5$SbO${}_6$