Critical spin liquid at 1/3 magnetization in a spin-1/2 triangular antiferromagnet

Abstract

Although magnetically ordered at low temperatures, the spin-1/2 triangular antiferromagnet Cs_2CuCl_4 exhibits remarkable spin dynamics that strongly suggest proximity to a spin liquid phase. Here we address the question of whether a proximate spin liquid may also occur in an applied magnetic field, leaving a similar imprint on the dynamical spin correlations of this material. Specifically, we explore a spatially anisotropic Heisenberg spin-1/2 triangular antiferromagnet at 1/3 magnetization from a dual vortex perspective, and indeed find a new ``critical'' spin liquid phase described by QED3 with an emergent SU(6) symmetry. A number of nontrivial predictions are given for the dynamical spin structure factor in this ``algebraic vortex liquid'' phase, which can be tested experimentally via inelastic neutron scattering. We also discuss how the well-studied ``up-up-down'' magnetization plateaus can be captured within our approach, and further predict the existence of a stable gapless solid phase in a weakly ordered up-up-down state. Finally, we predict several anomalous ``roton'' minima in the excitation spectrum in the regime of lattice anisotropy where the canted Neel state appears.

5 pages, 2 figures; expanded intro & discussion of theory; minor correction to structure factor

References in corpus (20)

• Chern Numbers in Discretized Brillouin Zone: Efficient Method of Computing (Spin) Hall Conductances
• Observation of extended scattering continua characteristic of spin fractionalization in the 2D frustrated quantum magnet Cs2CuCl4 by neutron scattering
• Topological Disorder Operators in Three-Dimensional Conformal Field Theory
• Direct Measurement of the Spin Hamiltonian and Observation of Condensation of Magnons in the 2D Frustrated Quantum Magnet Cs2CuCl4
• Magnetization plateaus in frustrated antiferromagnetic quantum spin models
• Spin correlations in the algebraic spin liquid - implications for high Tc superconductors
• Ordering in spatially anisotropic triangular antiferromagnets
• Anomalous Excitation Spectra of Frustrated Quantum Antiferromagnets
• Spin Liquid Phase in Anisotropic Triangular Lattice Heisenberg Model: Exact diagonalization and density-matrix renormalization group calculations
• Magnetic phase transitions in the two-dimensional frustrated quantum antiferromagnet Cs2CuCl4
• Large-N solutions of the Heisenberg and Hubbard-Heisenberg models on the anisotropic triangular lattice: application to Cs${}_2$CuCl${}_4$ and to the layered organic superconductors $\kappa$-(BEDT-TTF)${}_2$X
• Magnetization plateaux of S = 1/2 two-dimensional frustrated antiferromagnet Cs${}_2$CuBr${}_4$
• Criticality in quantum triangular antiferromagnets via fermionized vortices
• Algebraic vortex liquid in spin-1/2 triangular antiferromagnets: Scenario for Cs_2CuCl_4
• Ordering in Cs2CuCl4: Is there a proximate spin liquid?
• Theory of the algebraic vortex liquid in an anisotropic spin-1/2 triangular antiferromagnet
• Spin dynamics of the quasi two dimensional spin-1/2 quantum magnet Cs_2CuCl_4
• Statistics of spinons in the spin-liquid phase of Cs2CuCl4
• Spin Structure Factor of the Frustrated Quantum Magnet Cs_2CuCl_4
• Resonating valence bond wave function for the two dimensional fractional spin liquid

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• Thermodynamics of the Up-Up-Down Phase of the S = 1/2 Triangular-Lattice Antiferromagnet Cs${}_2$CuBr${}_4$
• Determination of effective microscopic models for the frustrated antiferromagnets Cs${}_2$CuCl${}_4$ and Cs${}_2$CuBr${}_4$ by density functional methods
• Monopole Quantum Numbers in the Staggered Flux Spin Liquid
• Spin-current order in anisotropic triangular antiferromagnets
• Quasiparticles of spatially anisotropic triangular antiferromagnets in a magnetic field
• Interplay of frustration and magnetic field in the two-dimensional quantum antiferromagnet Cu(tn)Cl${}_2$
• Magnetization plateaus of spin-$\frac{1}{2}$ system on a 5/7 skewed ladder
• Torque equilibrium spin wave theory study of anisotropy and Dzyaloshinskii-Moriya interaction effects on the indirect K$-$ edge RIXS spectrum of a triangular lattice antiferromagnet
• Magnon Spectrum of the Amorphous Ferromagnet Co${}_4$P from Atomistic Spin Dynamics
• Fermionized dual vortex theory for magnetized kagomé spin liquid