Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 2, 2016 | Submitted
Journal Article Open

Topological Defects on the Lattice I: The Ising model

Abstract

In this paper and its sequel, we construct topologically invariant defects in two-dimensional classical lattice models and quantum spin chains. We show how defect lines commute with the transfer matrix/Hamiltonian when they obey the defect commutation relations, cousins of the Yang–Baxter equation. These relations and their solutions can be extended to allow defect lines to branch and fuse, again with properties depending only on topology. In this part I, we focus on the simplest example, the Ising model. We define lattice spin-flip and duality defects and their branching, and prove they are topological. One useful consequence is a simple implementation of Kramers–Wannier duality on the torus and higher genus surfaces by using the fusion of duality defects. We use these topological defects to do simple calculations that yield exact properties of the conformal field theory describing the continuum limit. For example, the shift in momentum quantization with duality-twisted boundary conditions yields the conformal spin 1/16 of the chiral spin field. Even more strikingly, we derive the modular transformation matrices explicitly and exactly.

Additional Information

© 2016 IOP Publishing Ltd. Received 25 January 2016; Accepted for publication 7 March 2016; Published 9 August 2016. We thank Jason Alicea for illuminating discussions. DA gratefully acknowledges the support of the NSERC PGSD program. RM is grateful for support from the Sherman Fairchild Foundation and the Institute for Quantum Information and Matter.

Attached Files

Submitted - 1601.07185v1.pdf

Files

1601.07185v1.pdf
Files (2.2 MB)
Name Size Download all
md5:6cd998ab73335f80b1706fb3076a339d
2.2 MB Preview Download

Additional details

Created:
August 20, 2023
Modified:
October 18, 2023