Optical one-way quantum computing with a simulated valence-bond solid

TL;DR

This paper demonstrates the experimental generation of a photonic AKLT state, a valence-bond-solid ground state, and uses it to perform single-qubit quantum logic gates, advancing resource state preparation for one-way quantum computing.

Contribution

It is the first experimental realization of a photonic AKLT state used as a resource for one-way quantum computing.

Findings

Successfully generated a photonic AKLT state.

Implemented single-qubit quantum gates using the AKLT state.

Showed feasibility of using ground states of spin systems for quantum computation.

Abstract

One-way quantum computation proceeds by sequentially measuring individual spins (qubits) in an entangled many-spin resource state. It remains a challenge, however, to efficiently produce such resource states. Is it possible to reduce the task of generating these states to simply cooling a quantum many-body system to its ground state? Cluster states, the canonical resource for one-way quantum computing, do not naturally occur as ground states of physical systems. This led to a significant effort to identify alternative resource states that appear as ground states in spin lattices. An appealing candidate is a valence-bond-solid state described by Affleck, Kennedy, Lieb, and Tasaki (AKLT). It is the unique, gapped ground state for a two-body Hamiltonian on a spin-1 chain, and can be used as a resource for one-way quantum computing. Here, we experimentally generate a photonic AKLT state and use it to implement single-qubit quantum logic gates.