The Higgs Mode of Planar Coupled Spin-Ladders and its Observation in C${}_9$H${}_{18}$N${}_2$CuBr${}_4$

Abstract

Polarized inelastic neutron scattering experiments recently identified the amplitude (Higgs) mode in C${}_9$H${}_{18}$N${}_2$CuBr${}_4$, a two-dimensional near-quantum-critical spin-1/2 two-leg ladder compound, which exhibits a weak easy-axis exchange anisotropy. Here, we theoretically examine the dynamic spin structure factor of such planar coupled spin-ladder systems using large-scale quantum Monte Carlo simulations. This allows us to provide a quantitative account of the experimental neutron scattering data within a consistent quantum spin model. Moreover, we trance the details of the continuous evolution of the amplitude mode from a two-particle bound state of coupled ladders in the classical Ising limit all the way to the quantum spin-1/2 Heisenberg limit with fully restored SU(2) symmetry, where it gets overdamped by the two-magnon continuum in neutron scattering.

arXiv comment9 pages, 10 figures

References in corpus (21)

• Quantum Monte Carlo with Directed Loops
• Stochastic series expansion method with operator-loop update
• Solving the 3d Ising Model with the Conformal Bootstrap II. c-Minimization and Precise Critical Exponents
• Amplitude / Higgs Modes in Condensed Matter Physics
• Generalized Directed Loop Method for Quantum Monte Carlo Simulations
• Visibility of the Amplitude (Higgs) Mode in Condensed Matter
• Ground-State Phase Diagram of Quantum Heisenberg Antiferromagnets on the Anisotropic Dimerized Square Lattice
• Spectral functions of the Higgs mode near two-dimensional quantum critical points
• The Higgs mode in a two-dimensional superfluid
• Magnetic properties and spin waves of bilayer magnets in a uniform field
• Dynamical structure factors and excitation modes of the bilayer Heisenberg model
• Bound states in two-dimensional spin systems near the Ising limit: A quantum finite-lattice study
• Higgs amplitude mode in the vicinity of a $(2+1)$-dimensional quantum critical point
• Direct observation of the Higgs amplitude mode in a two-dimensional quantum antiferromagnet near the quantum critical point
• The amplitude mode in three-dimensional dimerized antiferromagnets
• Universal Properties of the Higgs Resonance in (2+1)-Dimensional U(1) Critical Systems
• Field induced spontaneous quasiparticle decay and renormalization of quasiparticle dispersion in a quantum antiferromagnet
• Critical capacitance and charge-vortex duality near the superfluid to insulator transition
• Excitation Gap Scaling near Quantum Critical Three-Dimensional Antiferromagnets
• Higgs Mode and Magnon Interactions in 2D Quantum Antiferromagnets from Raman Scattering
• Magnetic ordering induced by interladder coupling in the spin-1/2 Heisenberg two-leg ladder antiferromagnet C${}_9$H${}_{18}$N${}_2$CuBr${}_4$

Cited by in corpus (10)

• Progress on stochastic analytic continuation of quantum Monte Carlo data
• Spin dynamics of itinerant electrons: local magnetic moment formation and Berry phase
• Fractional and composite excitations of antiferromagnetic quantum spin trimer chains
• Evidence for pressure induced unconventional quantum criticality in the coupled spin ladder antiferromagnet C${}_9$H${}_{18}$N${}_2$CuBr${}_4$
• Continuous similarity transformation for critical phenomena: easy-axis antiferromagnetic XXZ model
• Stable Higgs mode in anisotropic quantum magnets
• Magnetic excitations in magnetization plateaux of a frustrated spin ladder
• First ESR Detection of Higgs Amplitude Mode and Analysis with Extended Spin-Wave Theory in Dimer System KCuCl${}_3$
• Why the Schwinger Boson mean field theory fails to describe the spin dynamics of the triangular lattice antiferromagnetic Heisenberg model?
• Gapless Higgs Mode in the Fulde-Ferrell-Larkin-Ovchinnikov State of a Superconductor