Monopoles in Dirac spin liquids and their symmetries from instanton calculus
Shankar Ganesh, Joseph Maciejko
SciPost Phys. 16, 118 (2024) · published 2 May 2024
- doi: 10.21468/SciPostPhys.16.5.118
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Abstract
The Dirac spin liquid (DSL) is a two-dimensional (2D) fractionalized Mott insulator featuring massless Dirac spinon excitations coupled to a compact U(1) gauge field, which allows for flux-tunneling instanton events described by magnetic monopoles in (2+1)D Euclidean spacetime. The state-operator correspondence of conformal field theory has been used recently to define associated monopole operators and determine their quantum numbers, which encode the microscopic symmetries of conventional ordered phases proximate to the DSL. In this work, we utilize semiclassical instanton methods not relying on conformal invariance to construct monopole operators directly in (2+1)D spacetime as instanton-induced 't Hooft vertices, i.e., fermion-number-violating effective interactions originating from zero modes of the Euclidean Dirac operator in an instanton background. In the presence of a flavor-adjoint fermion mass, resummation of the instanton gas is shown to select the correct monopole to be proliferated, in accordance with predictions of the state-operator correspondence. We also show that our instanton-based approach is able to determine monopole quantum numbers on bipartite lattices.
Authors / Affiliation: mappings to Contributors and Organizations
See all Organizations.- Canada Research Chairs
- Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada (through Organization: Conseil de Recherches en Sciences Naturelles et en GĂ©nie / Natural Sciences and Engineering Research Council [NSERC / CRSNG])
- Government of Alberta
- Pacific Institute for the Mathematical Sciences
- University of Alberta [UAlberta]