Generalized Haldane map from the matrix product state path integral to the critical theory of the J_{1}-J_{2} chain

We study the J_{1}-J_{2} spin-1/2 chain using a path integral constructed over matrix product states (MPS). By virtue of its nontrivial entanglement structure, the MPS ansatz captures the key phases of the model even at a semiclassical, saddle-point level, and, as a variational state, is in good agr...

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Bibliographic Details
Main Authors: F. Azad, Adam J. McRoberts, Chris Hooley, A. G. Green
Format: Article
Language:English
Published: American Physical Society 2025-02-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.7.L012037
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Summary:We study the J_{1}-J_{2} spin-1/2 chain using a path integral constructed over matrix product states (MPS). By virtue of its nontrivial entanglement structure, the MPS ansatz captures the key phases of the model even at a semiclassical, saddle-point level, and, as a variational state, is in good agreement with the field theory obtained by Abelian bosonization. Going beyond the semiclassical level, we show that the MPS ansatz facilitates a physically motivated derivation of the field theory of the critical phase: By carefully taking the continuum limit—a generalization of the Haldane map—we recover from the MPS path integral a field theory with the correct topological term and emergent SO(4) symmetry, constructively linking the microscopic states and topological field-theoretic structures. Moreover, the dimerization transition is particularly clear in the MPS formulation—an explicit dimerization potential becomes relevant, gapping out the magnetic fluctuations.
ISSN:2643-1564