Topological defects of Néel order and Kondo singlet formation for Kondo-Heisenberg model on a honeycomb lattice

Abstract

Heavy fermion systems represent a prototypical setting to study magnetic quantum phase transitions. A particular focus has been on the physics of Kondo destruction, which captures quantum criticality beyond the Landau framework of order-parameter fluctuations. In this context, we study the spin one-half Kondo-Heisenberg model on a honeycomb lattice at half filling. The problem is approached from the Kondo destroyed, antiferromagnetically ordered insulating phase. We describe the local moments in terms of a coarse grained quantum non-linear sigma model, and show that the skyrmion defects of the antiferromagnetic order parameter host a number of competing order parameters. In addition to the spin Peierls, charge and current density wave order parameters, we identify for the first time Kondo singlets as the competing orders of the antiferromagnetism. We show that the antiferromagnetism and various competing singlet orders can be related to each other via generalized chiral transformations of the underlying fermions. We also show that the conduction electrons acquire a Berry phase through their coupling to the hedgehog configurations of the Néel order, which cancels the Berry phase of the local moments. Our results demonstrate the competition between the Kondo-singlet formation and spin-Peierls order when the antiferromagnetic order is suppressed, thereby shedding new light on the global phase diagram of heavy fermion systems at zero temperature.

14 pages, 4 figures

References in corpus (17)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• "Deconfined" quantum critical points
• Heavy Fermions and Quantum Phase Transitions
• Weak magnetism and non-Fermi liquids near heavy-fermion critical points
• Electron fractionalization in two-dimensional graphenelike structures
• Algebraic spin liquid as the mother of many competing orders
• Frustration and the Kondo effect in heavy fermion materials
• Chiral Gauge Theory for Graphene
• Many-body spin Berry phases emerging from the $\pi$-flux state: antiferromagnetic/valence-bond-solid competition
• Quantum phase transitions in heavy fermion metals and Kondo insulators
• Magnetic field tuned quantum criticality of heavy fermion system YbPtBi
• Fermi surface and antiferromagnetism in the Kondo lattice: an asymptotically exact solution in d>1 Dimensions
• Global Phase Diagram of the Kondo Lattice: From Heavy Fermion Metals to Kondo Insulators
• Geometric phases and competing orders in two dimensions
• Field-induced long-range magnetic order in the spin-singlet ground state system YbAl3C3: Neutron diffraction study
• Charge-$2e$ Skyrmion condensate in a hidden order state
• Conserved charges of order-parameter textures in Dirac systems

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• Non-Abelian bosonization in a (3+1)-d Kondo semimetal via quantum anomalies
• Competing Orders and Anomalies
• Color degeneracy of competing orders near topological defects cores in planar quadratic band touching systems
• Dynamic zero modes of Dirac fermions and competing singlet phases of antiferromagnetic order
• Mechanism of skyrmion condensation and pairing for twisted bi-layer graphene
• Topological quantum control: Edge currents via Floquet depinning of skyrmions in the $\nu =0$ graphene quantum Hall antiferromagnet