Foliated BF theories and Multipole symmetries

TL;DR

This paper introduces $ ext{Z}_N$ foliated BF theories in 2+1 dimensions to model fracton phases, revealing size-dependent ground state degeneracy linked to multipole symmetries and stacking of topological layers.

Contribution

It constructs new foliated BF theories incorporating multipole symmetries, providing a unified field-theoretic framework for fracton and unconventional topological phases.

Findings

Ground state degeneracy depends on system size and gcd with N.

Foliated BF theories capture UV lattice model features of fracton phases.

Theories unify understanding of fracton and unconventional topological phases.

Abstract

Due to the recent studies of the fracton topological phases, which host deconfined quasi-particle excitations with mobility restrictions, the concept of symmetries have been updated. Focusing on one of such new symmetries, multipole symmetries, including global, dipole, and quadruple symmetries, and gauge fields associated with them, we construct a new sets of $\mathbb{Z}_N$ $2+1d$ foliated BF theories, where BF theories of conventional topological phases are stacked in layers with couplings between them. By investigating gauge invariant non-local operators, we show that our foliated BF theories exhibit unusual ground state degeneracy depending on the system size; it depends on the greatest common divisor between $N$ and the system size. Our result provides a unified insight on UV lattice models of the fracton topological phases and other unconventional ones in view of foliated field theories.