Physical states and finite-size effects in Kitaev's honeycomb model: Bond disorder, spin excitations, and NMR lineshape

Abstract

Kitaev's compass model on the honeycomb lattice realizes a spin liquid whose emergent excitations are dispersive Majorana fermions and static Z_2 gauge fluxes. We discuss the proper selection of physical states for finite-size simulations in the Majorana representation, based on a recent paper by Pedrocchi, Chesi, and Loss [Phys. Rev. B 84, 165414 (2011)]. Certain physical observables acquire large finite-size effects, in particular if the ground state is not fermion-free, which we prove to generally apply to the system in the gapless phase and with periodic boundary conditions. To illustrate our findings, we compute the static and dynamic spin susceptibilities for finite-size systems. Specifically, we consider random-bond disorder (which preserves the solubility of the model), calculate the distribution of local flux gaps, and extract the NMR lineshape. We also predict a transition to a random-flux state with increasing disorder.

13 pages, 10 figs; (v2) final version as published

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Cited by in corpus (14)

• Thermodynamic and Transport Properties in Disordered Kitaev Models
• Thermodynamic classification of three-dimensional Kitaev spin liquids
• Observation of a random singlet state in a diluted Kitaev honeycomb material
• Susceptibility anisotropy and its disorder evolution in models for Kitaev materials
• Nonlinear response of the Kitaev honeycomb lattice model in a weak magnetic field
• Bound states of fractionalized excitations in a modulated Kitaev spin liquid
• Raman Scattering Polarization and Single Spinon Identification in Two-Dimensional Kitaev Quantum Spin Liquids
• Projective-symmetry-group analysis of inelastic light scattering in Kitaev spin balls
• Quantum Spin Liquid phases in Kitaev Materials
• Anyon polarons as a window into competing phases of the Kitaev honeycomb model under a Zeeman field
• Digital Quantum Simulation of the Kitaev Quantum Spin Liquid
• The Kekulé-Kitaev model: linear and non-linear responses and magnetic field effects
• Tunable anyonic permeability across ${\mathbb{Z}}_2$ spin liquid junctions
• Majorana Signatures in Planar Tunneling through a Kitaev Spin Liquid