Multidimensional Hyperentangled Photon Graph States: Creation, Validation and Application

Descripción del proyecto

Construir la próxima generación de luz cuántica

En la frontera de la ciencia cuántica se encuentra el entrelazamiento. Es el misterioso vínculo que permite a las partículas compartir información de forma instantánea. Aprovechar este fenómeno podría impulsar la próxima revolución cuántica, permitiendo comunicaciones ultraseguras y nuevas y potentes arquitecturas informáticas. Sin embargo, crear grandes redes de fotones entrelazados sigue siendo uno de los retos más difíciles de la física. El proyecto HyperGraph, financiado por el Consejo Europeo de Investigación, pretende cambiar esta situación. Utilizando una innovadora interfaz espín-fotón basada en el diamante con una eficacia sin precedentes, los investigadores generarán vastas redes bidimensionales y tridimensionales de luz entrelazada. Estos «estados de grafos» cuánticos son aquellos que los ordenadores clásicos no pueden modelar. Se espera que estos sistemas inspiren avances en la corrección de errores, el procesamiento cuántico de la información y el diseño de dispositivos cuánticos totalmente nuevos.

Objetivo

At the heart of quantum physics and quantum technology lies the captivating phenomenon of entanglement, which society hopes to profit from in improved and completely novel technical applications within the second quantum revolution.

Entangled quantum states are extremely difficult to create and validate; only 50 years ago entangled states were shown to violate Bell’s inequalities, using two entangled quantized states of electromagnetic radiation, known as single photon states. For this achievement the 2022 Nobel Prize in Physics was awarded.

Ever since, entangled states have driven fundamental and applied research. Intriguingly, entanglement can theoretically be created between an arbitrary number of photons. Their creation, however, has been very challenging, and over the past years, the size of one-dimensional entangled photon states has been increased to 14 in 2022. The slow progress is mainly limited by the development of deterministic single photon sources.

Recently, I have designed a novel spin-photon interface in diamond with record-high emitter to detector efficiencies theoretically exceeding 99% and realistically reaching 90%. These record efficiencies are enabled by the Sawfish interface. Multiplexing of several of such interfaces will enable the creation of large 2D and even 3D photon graph states.

These states will be so complex, that new theoretical models are required for their understanding. The usage of states whose density matrix could never be computed on classical computers is indeed a conceptual problem in theory. In this regime, HyperGraph’s experimental research will stimulate concepts and new discoveries in theory. Moreover, because of the many degrees of interconnection between the individual qubits, I expect innovative concepts for error correction, novel and possibly improved protocols in fault tolerant quantum information processing, and even completely new application cases to be developed in parallel and beyond HyperGraph.