Doping a topological quantum spin liquid: slow holes in the Kitaev honeycomb model

We present a controlled microscopic study of mobile holes in the spatially anisotropic (Abelian) gapped phase of the Kitaev honeycomb model. We address the properties of (i) a single hole [its internal degrees of freedom as well as its hopping properties]; (ii) a pair of holes [their (relative) part...

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Main Authors: Halász, G, Chalker, J, Moessner, R
Format: Journal article
Language:English
Published: American Physical Society 2014
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author Halász, G
Chalker, J
Moessner, R
author_facet Halász, G
Chalker, J
Moessner, R
author_sort Halász, G
collection OXFORD
description We present a controlled microscopic study of mobile holes in the spatially anisotropic (Abelian) gapped phase of the Kitaev honeycomb model. We address the properties of (i) a single hole [its internal degrees of freedom as well as its hopping properties]; (ii) a pair of holes [their (relative) particle statistics and interactions]; (iii) the collective state for a finite density of holes. We find that each hole in the doped model has an eight-dimensional internal space, characterized by three internal quantum numbers: the first two "fractional" quantum numbers describe the binding to the hole of the fractional excitations (fluxes and fermions) of the undoped model, while the third "spin" quantum number determines the local magnetization around the hole. The fractional quantum numbers also encode fundamentally distinct particle properties, topologically robust against small local perturbations: some holes are free to hop in two dimensions, while others are confined to hop in one dimension only; distinct hole types have different particle statistics, and in particular, some of them exhibit non-trivial (anyonic) relative statistics. These particle properties in turn determine the physical properties of the multi-hole ground state at finite doping, and we identify two distinct ground states with different hole types that are stable for different model parameters. The respective hopping dimensionalities manifest themselves in an electrical conductivity approximately isotropic in one ground state and extremely anisotropic in the other one. We also compare our microscopic study with related mean-field treatments, and discuss the main discrepancies between the two approaches, which in particular involve the possibility of binding fractional excitations as well as the particle statistics of the holes.
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spelling oxford-uuid:1198f9a7-adf9-4aff-9daf-4ef17e7aa5d02022-03-26T10:03:11ZDoping a topological quantum spin liquid: slow holes in the Kitaev honeycomb modelJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:1198f9a7-adf9-4aff-9daf-4ef17e7aa5d0EnglishSymplectic Elements at OxfordAmerican Physical Society2014Halász, GChalker, JMoessner, RWe present a controlled microscopic study of mobile holes in the spatially anisotropic (Abelian) gapped phase of the Kitaev honeycomb model. We address the properties of (i) a single hole [its internal degrees of freedom as well as its hopping properties]; (ii) a pair of holes [their (relative) particle statistics and interactions]; (iii) the collective state for a finite density of holes. We find that each hole in the doped model has an eight-dimensional internal space, characterized by three internal quantum numbers: the first two "fractional" quantum numbers describe the binding to the hole of the fractional excitations (fluxes and fermions) of the undoped model, while the third "spin" quantum number determines the local magnetization around the hole. The fractional quantum numbers also encode fundamentally distinct particle properties, topologically robust against small local perturbations: some holes are free to hop in two dimensions, while others are confined to hop in one dimension only; distinct hole types have different particle statistics, and in particular, some of them exhibit non-trivial (anyonic) relative statistics. These particle properties in turn determine the physical properties of the multi-hole ground state at finite doping, and we identify two distinct ground states with different hole types that are stable for different model parameters. The respective hopping dimensionalities manifest themselves in an electrical conductivity approximately isotropic in one ground state and extremely anisotropic in the other one. We also compare our microscopic study with related mean-field treatments, and discuss the main discrepancies between the two approaches, which in particular involve the possibility of binding fractional excitations as well as the particle statistics of the holes.
spellingShingle Halász, G
Chalker, J
Moessner, R
Doping a topological quantum spin liquid: slow holes in the Kitaev honeycomb model
title Doping a topological quantum spin liquid: slow holes in the Kitaev honeycomb model
title_full Doping a topological quantum spin liquid: slow holes in the Kitaev honeycomb model
title_fullStr Doping a topological quantum spin liquid: slow holes in the Kitaev honeycomb model
title_full_unstemmed Doping a topological quantum spin liquid: slow holes in the Kitaev honeycomb model
title_short Doping a topological quantum spin liquid: slow holes in the Kitaev honeycomb model
title_sort doping a topological quantum spin liquid slow holes in the kitaev honeycomb model
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AT chalkerj dopingatopologicalquantumspinliquidslowholesinthekitaevhoneycombmodel
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