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Constructing a variational ground state of matter fermions coupled to a vison pair in Kitaev's honeycomb model

Theo Grace* and Alessandro Principi†

  • *Contact author: theo.grace@manchester.ac.uk
  • †Contact author: alessandro.principi@manchester.ac.uk
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Phys. Rev. B 113, 115122 – Published 11 March, 2026

DOI: https://doi.org/10.1103/t64v-ch2p

Abstract

We develop a method to construct simple and explicit variational approximations for the ground state of Kitaev's honeycomb model with a nontrivial Z2 flux configuration consisting of a pair of visons on neighboring plaquettes. The method consists of retaining only the largest singular values of the generator of the transformation between the vison pair and flux-free ground states. We compare physical quantities calculated using the approximate state to those obtained by extrapolating the results of exact diagonalization of finite lattices, finding them to be in very good agreement. We discuss ways to extend the method to more complicated flux configurations.

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Phys. Rev. B 113, 115122– Published 11 March, 2026
  • Received 2 December 2025
  • Accepted 18 February 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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