Edge modes, extended TQFT, and measurement based quantum computation

TL;DR

This paper reformulates measurement-based quantum computation as an extended topological field theory, offering new insights into the relation between circuit models and entanglement gauge theories with edge modes representing logical qubits.

Contribution

It introduces an alternative extended TQFT formulation of entanglement gauge theory for MBQC, linking edge modes to logical qubits and providing a new perspective on quantum computation models.

Findings

Extended TQFT provides a new framework for MBQC.

Edge modes in gauge theories correspond to logical qubits.

Offers a novel interpretation of the circuit-MBQC relationship.

Abstract

Quantum teleportation can be used to define a notion of parallel transport which characterizes the entanglement structure of a quantum state \cite{Czech:2018kvg}. This suggests one can formulate a gauge theory of entanglement. In \cite{Wong:2022mnv}, it was explained that measurement based quantum computation in one dimension can be understood in term of such a gauge theory (MBQC). In this work, we give an alternative formulation of this "entanglement gauge theory" as an extended topological field theory. This formulation gives a alternative perspective on the relation between the circuit model and MBQC. In addition, it provides an interpretation of MBQC in terms of the extended Hilbert space construction in gauge theories, in which the entanglement edge modes play the role of the logical qubit.