Non-local Order Parameters and Quantum Entanglement for Fermionic Topological Field Theories

TL;DR

This paper investigates non-local order parameters and entanglement measures in fermionic topological phases, establishing their connection to topological invariants and formulating them within topological quantum field theories.

Contribution

It introduces a formulation of quantized non-local order parameters and entanglement measures within state sum TQFTs for fermionic topological phases with orientation-reversing symmetry.

Findings

Order parameters are topological invariants.

Entanglement negativity corresponds to path integrals with specific spin structures.

Framework clarifies the topological nature of fermionic phases.

Abstract

We study quantized non-local order parameters, constructed by using partial time-reversal and partial reflection, for fermionic topological phases of matter in one spatial dimension protected by an orientation reversing symmetry, using topological quantum field theories (TQFTs). By formulating the order parameters in the Hilbert space of state sum TQFT, we establish the connection between the quantized non-local order parameters and the underlying field theory, clarifying the nature of the order parameters as topological invariants. We also formulate several entanglement measures including the entanglement negativity on state sum spin TQFT, and describe the exact correspondence of the entanglement measures to path integrals on a closed surface equipped with a specific spin structure.