# Photonic tensor networks produced by a single quantum emitter

## TL;DR

This paper introduces a protocol for generating two-dimensional tensor network states using a single quantum emitter interacting sequentially with a qubit string, enabling complex quantum states for computation.

## Contribution

It presents a novel method to produce 2D tensor network states with a single quantum system, including a protocol for creating 2D cluster states in nanophotonics.

## Key findings

- Identifies classes of many-body states achievable with the protocol
- Proposes a deterministic method for 2D cluster state creation
- Enables quantum computation with a single atom and light

## Abstract

We propose and analyze a protocol to generate two dimensional tensor network states using a single quantum system that sequentially interacts with a 1D string of qubits. This is accomplished by using parts of the string itself as a quantum queue memory. As a physical implementation, we consider a single atom or atom like system coupled to a 1D waveguide with a distant mirror, where guided photons represent the qubits while the mirror allows the implementation of the queue memory. We identify the class of many-body quantum states that can be produced using this approach. These include universal resources for measurement based quantum computation and states associated with topologically ordered phases. We discuss an explicit protocol to deterministically create a 2D cluster state in a quantum nanophotonic experiment, that allows for a realization of a quantum computer using a single atom coupled to light.