SciPost logo

SciPost Submission Page

Fractionalization of Coset Non-Invertible Symmetry and Exotic Hall Conductance

by Po-Shen Hsin, Ryohei Kobayashi, Carolyn Zhang

This Submission thread is now published as

Submission summary

Authors (as registered SciPost users): Po-Shen Hsin · Ryohei Kobayashi
Submission information
Preprint Link: scipost_202408_00025v1  (pdf)
Date accepted: 2024-09-13
Date submitted: 2024-08-22 02:35
Submitted by: Kobayashi, Ryohei
Submitted to: SciPost Physics
Ontological classification
Academic field: Physics
Specialties:
  • Condensed Matter Physics - Theory
  • High-Energy Physics - Theory
Approach: Theoretical

Abstract

We investigate fractionalization of non-invertible symmetry in (2+1)D topological orders. We focus on coset non-invertible symmetries obtained by gauging non-normal subgroups of invertible $0$-form symmetries. These symmetries can arise as global symmetries in quantum spin liquids, given by the quotient of the projective symmetry group by a non-normal subgroup as invariant gauge group. We point out that such coset non-invertible symmetries in topological orders can exhibit symmetry fractionalization: each anyon can carry a "fractional charge" under the coset non-invertible symmetry given by a gauge invariant superposition of fractional quantum numbers. We present various examples using field theories and quantum double lattice models, such as fractional quantum Hall systems with charge conjugation symmetry gauged and finite group gauge theory from gauging a non-normal subgroup. They include symmetry enriched $S_3$ and $O(2)$ gauge theories. We show that such systems have a fractionalized continuous non-invertible coset symmetry and a well-defined electric Hall conductance. The coset symmetry enforces a gapless edge state if the boundary preserves the continuous non-invertible symmetry. We propose a general approach for constructing coset symmetry defects using a "sandwich" construction: non-invertible symmetry defects can generally be constructed from an invertible defect sandwiched by condensation defects. The anomaly free condition for finite coset symmetry is also identified.

Author indications on fulfilling journal expectations

  • Provide a novel and synergetic link between different research areas.
  • Open a new pathway in an existing or a new research direction, with clear potential for multi-pronged follow-up work
  • Detail a groundbreaking theoretical/experimental/computational discovery
  • Present a breakthrough on a previously-identified and long-standing research stumbling block

Author comments upon resubmission

We thank the referees for careful reading of the manuscript and helpful comments on the draft.

List of changes

1. In response to Report 1. 1, below (3.1) we added the comment that the orbit [g] has the length |K|/|K_g| for the stabilizer group K_g of the group element g.
2. In response to Report 1. 2, above Section 3.3.2, we added a few sentences to connect the coset symmetry to the non-invertible domain wall in U(1)8 from condensing the charge 4 Wilson line. We also cited 1012.0911.
3. In response to Report 1. 3, at the beginning of Section 6 we added a description of the parton construction for the spin liquids.
4. In response to Report 2, we omitted the word "continuous" since the construction is valid for either G is continuous or discrete.

Published as SciPost Phys. 17, 095 (2024)


Reports on this Submission

Report #2 by Anonymous (Referee 1) on 2024-8-29 (Invited Report)

Report

I think the updated version is good and ready to be published.

Recommendation

Publish (easily meets expectations and criteria for this Journal; among top 50%)

  • validity: -
  • significance: -
  • originality: -
  • clarity: -
  • formatting: -
  • grammar: -

Report #1 by Anonymous (Referee 2) on 2024-8-22 (Invited Report)

Report

The new version sounds good to me, but I wish the authors had addressed my first two comments.

Recommendation

Publish (meets expectations and criteria for this Journal)

  • validity: -
  • significance: -
  • originality: -
  • clarity: -
  • formatting: -
  • grammar: -

Login to report or comment