Quantum kagome antiferromagnet in a magnetic field: Low-lying non-magnetic excitations versus valence-bond crystal order

Abstract

We study the ground state properties of a quantum antiferromagnet on the kagome lattice in the presence of a magnetic field, paying particular attention to the stability of the plateau at magnetization 1/3 of saturation and the nature of its ground state. We discuss fluctuations around classical ground states and argue that quantum and classical calculations at the harmonic level do not lead to the same result in contrast to the zero-field case. For spin S=1/2 we find a magnetic gap below which an exponential number of non-magnetic excitations are present. Moreover, such non-magnetic excitations also have a (much smaller) gap above the three-fold degenerate ground state. We provide evidence that the ground state has long-range order of valence-bond crystal type with nine spins in the unit cell.

5 pages including 4 figures, uses REVTeX4; final version with some small extensions; to appear in Phys. Rev. B

References in corpus (19)

• Ising models of quantum frustration
• First excitations of the spin 1/2 Heisenberg antiferromagnet on the kagomé lattice
• Order versus Disorder in the Quantum Heisenberg Antiferromagnet on the Kagom{é} lattice: an approach through exact spectra analysis
• Macroscopic magnetization jumps due to independent magnons in frustrated quantum spin lattices
• Spin-1/2 Kagome Like Lattice in Volborthite Cu3V2O7(OH)2-H2O
• Low-energy sector of the S=1/2 Kagome antiferromagnet
• Atomic quantum gases in Kagomé lattices
• Two-dimensional periodic frustrated Ising models in a transverse field
• Magnetization plateaus in frustrated antiferromagnetic quantum spin models
• Physics of low energy singlet states of the Kagome lattice quantum Heisenberg antiferromagnet
• The phase diagram of the hexagonal lattice quantum dimer model
• Quantum magnetism in two dimensions: From semi-classical Néel order to magnetic disorder
• Field induced transitions in a kagome antiferromagnet
• Magnetization Process of the S=1 and 1/2 Uniform and Distorted Kagome Heisenberg Antiferromagnets
• Magnets with strong geometric frustration
• Hidden long range order in Heisenberg Kagome antiferromagnets
• From classical to quantum Kagome antiferromagnet in a magnetic field
• Exact diagonalization Studies of Two-dimensional Frustrated Antiferromagnet Models
• Field-Induced Order and Magnetization Plateaux in Frustrated Antiferromagnets

Cited by in corpus (49)

• Controlling frustrated liquids and solids with an applied field in a kagome Heisenberg antiferromagnet
• Electronic Orbital Currents and Polarization in Mott Insulators
• Effects of frustration on magnetic molecules: a survey from Olivier Kahn till today
• Valence Bond Solids and Their Quantum Melting in Hard-Core Bosons on the Kagome Lattice
• Quantum Spin Ice and dimer models with Rydberg atoms
• Numerical study of magnetization plateaux in the spin-1/2 kagome Heisenberg antiferromagnet
• Critical magnetization behaviors of the triangular and Kagome lattice quantum antiferromagnets
• Highly Frustrated Magnetic Clusters: The kagome on a sphere
• Spin nematics and magnetization plateau transition in anisotropic Kagome magnets
• High-Order Coupled Cluster Method Study of Frustrated and Unfrustrated Quantum Magnets in External Magnetic Fields
• Magnetic behavior of volborthite Cu3V2O7(OH)2(H2O)2 determined by coupled trimers rather than frustrated chains
• Lattice gas description of pyrochlore and checkerboard antiferromagnets in a strong magnetic field
• Magnon crystallization in the kagome lattice antiferromagnet
• Linear independence of localized magnon states
• Exact solution of the geometrically frustrated spin-1/2 Ising-Heisenberg model on the triangulated Kagome (triangles-in-triangles) lattice
• Chern-Simons theory of the magnetization plateaus of the spin-1/2 quantum XXZ Heisenberg model on Kagome Lattice
• Coupled frustrated quantum spin-1/2 chains with orbital order in volborthite Cu3V2O7(OH)2(H2O)2
• Anomalous Behavior of the Magnetization Process of the S = 1/2 Kagome-Lattice Heisenberg Antiferromagnet at One-Third Height of the Saturation
• Magnetization Jump in the Magnetization Process of the spin-1/2 Heisenberg Antiferromagnet on a Distorted Square-Kagome Lattice
• Magnetization Process of the Spin-S Kagome-Lattice Heisenberg Antiferromagnet
• A striped supersolid phase and the search for deconfined quantum criticality in hard-core bosons on the triangular lattice
• Fermionic spin excitations in two and three-dimensional antiferromagnets
• Semiclassical theory of the magnetization process of the triangular lattice Heisenberg model
• Atomic Fermi gas in the trimerized Kagomé lattice at the filling 2/3
• Real-space perturbation theory for frustrated magnets: application to magnetization plateaus
• The spin-1/2 Kagome XXZ model in a field: competition between lattice nematic and solid orders
• Superfluid-Insulator transitions of bosons on Kagome lattice at non-integer fillings
• Kinetic frustration induced supersolid in the $S=1/2$ kagome lattice antiferromagnet in a magnetic field
• Dynamical dimer correlations at bipartite and non-bipartite Rokhsar-Kivelson points
• Staircase of crystal phases of hard-core bosons on the Kagome lattice
• Semiclassical degeneracies and ordering for highly frustrated magnets in a field
• Dynamical stability of the quantum Lifshitz theory in 2+1 Dimensions
• Numerical evidence for a chiral spin liquid in the XXZ antiferromagnetic Heisenberg model on the kagome lattice at $m=\frac{2}{3}$ magnetization
• Ordered Phases of the Anisotropic Kagome Lattice Antiferromagnet in a Field
• Correlated spin liquids in the quantum kagome antiferromagnet at finite field: a renormalisation group analysis
• Asymmetric melting of one-third plateau in kagome quantum antiferromagnets
• Melting of magnetization plateaus for kagome and square-kagome lattice antiferromagnets
• Statistics of holes and nature of superfluid phases in Quantum dimer models
• Order by disorder and phase transitions in a highly frustrated spin model on the triangular lattice
• Selection of factorizable ground state in a frustrated spin tube: Order by disorder and hidden ferromagnetism
• Quantum half-orphans in kagome antiferromagnets
• Unconventional magnets in external magnetic fields
• Machine learning as an improved estimator for magnetization curve and spin gap
• Finite-temperature ordering in a two-dimensional highly frustrated spin model
• Thermodynamic properties of the macroscopically degenerate tetramer-dimer phase of the spin-1/2 Heisenberg model on the diamond-decorated square lattice
• Loop-gas description of the localized-magnon states on the kagome lattice with open boundary conditions
• The role of multiplicative noise in critical dynamics
• Strong-coupling expansion and effective hamiltonians
• Mott phases and quantum phase transitions of extended Bose-Hubbard models in 2+1 dimensions