Resources for universal quantum state manipulation and engineering

TL;DR

This paper explores the non-Gaussian resources required for universal quantum state manipulation in multimode quantum optics, demonstrating that finite Fock basis states suffice and providing a scheme for implementing nonlinear gates.

Contribution

It identifies the necessary non-Gaussian resources for universal quantum gate implementation and presents a probabilistic scheme using resource states and Gaussian operations.

Findings

Finite Fock basis states are sufficient for universal quantum gates.

An explicit probabilistic scheme for the nonlinear sign gate is proposed.

Non-Gaussian resources enable universal quantum state manipulation.

Abstract

We investigate which non-Gaussian resources are needed, in addition to Gaussian operations and measurements, for implementation of arbitrary quantum gates on multimode quantum states of light. We show that an arbitrary set of states with finite expansion in Fock basis is sufficient for this task. As an illustration we present an explicit scheme for probabilistic implementation of the nonlinear sign gate using resource non-Gaussian states and Gaussian operations.