# Will light be the basis for quantum computing?

December 03, 2018Using a compact optical platform that exploits the quantum characteristics of light, Professor Roberto Morandotti and his team are one step closer to realizing the first powerful photonic quantum computer. In the journal

*Nature Physics*, the INRS researchers revealed to have generated a particular class of quantum states-d-level cluster states-, as well as to have used them to implement novel quantum operations. The demonstrated states exhibit unique properties that make them more robust and powerful than any other such states demonstrated thus far.

For nearly ten years, Professor Roberto Morandotti has been building an ambitious system piece by piece by developing chips that use light particles (photons) as the data medium. On these coin-sized chip structures, photons are generated and transformed so they can be assigned unique quantum properties. His team was the first to successfully create high-dimensional (i.e. quDit) optical cluster states, one of the elements that can enable the ongoing quest to harness the power of quantum computing.

Electronic computer systems are nearing the limit of their capabilities, yet demand for greater computing power is constantly growing. This is why scientists are turning to quantum computing, investigating how to encode a significant amount of information in light particles and perform calculations of unprecedented complexity.

To get there, the data medium has to be shifted to quantum bits (or qubits), the non-classical computing equivalent of conventional bits. By judiciously designing the quantum state of the photons, it is possible to increase the information storage capacity of qubits and boost them to obtain so-called quDits. Then, by grouping the quDits into clusters, quantum computing operations based on the so called 'one-way' scheme become possible.

Other approaches to quantum computing use ions, atoms, or other quantum resources, but the efforts to manipulate them towards a higher-dimensional encoding have been inefficient. According to Professor José Azaña (INRS), an expert of telecommunications who contributed to this research, photons also present another advantage: "They are used to transmit information via optical fibers in existing telecommunications systems. That means photons with controlled quantum properties can also travel through these same channels without losing their attributes."

The complexity and richness of the cluster states described in the article in

*Nature Physics*is unprecedented. Moreover, the team of researchers also achieved another first by performing high-dimensional quantum computing operations harnessing the realized cluster states.

They demonstrated that light has all the necessary features to power the superfast computers of the future. In a significant leap forward, this was done with a compact system compatible with existing technologies. The platform developed by the INRS team is capable of generating quantum states with complexities sufficient to achieve quantum computing objectives, thus paving the way to one-way quantum computers.

-end-

**ARTICLE HIGHLIGHTS**

Firsts:

Firsts:

- - Generation of high-dimensional cluster states

- D-level operations using cluster states

- Creation of a hyper-entangled state in frequency and time

**Advantages of the photonic system:**

- - Commercially available components

- Compatible with integrated electronics systems

- Compatible with telecommunications systems

- Scalability

- Practical and easy to use

- Inexpensive

- Compact

**ABOUT THE PAPER**

Christian Reimer, Stefania Sciara, Piotr Roztocki, Mehedi Islam, Luis Romero Cortés, Yanbing Zhang, Bennet Fischer, Sébastien Loranger, Raman Kashyap, Alfonso Cino, Sai T. Chu, Brent E. Little, David J. Moss, Lucia Caspani, William J. Munro, José Azan?a, Michael Kues and Roberto Morandotti, "High-dimensional one-way quantum processing implemented on d-level cluster states,"

*Nature Physics*, published December 3, 2018, DOI: 10.1038/s41567-018-0347-x.

The research team received financial support from the Natural Sciences and Engineering Research Council of Canada, Ministère de l'Économie, de la Science et de l'Innovation du Québec, Canada Research Chairs, the Australian Research Council, the European Union, the Chinese Academy of Sciences, the John Templeton Foundation, the Government of the Russian Federation, and the 1,000 Talents Program (Sichuan, China).

**ABOUT INRS**

Institut national de la recherche scientifique is the only institution in Quebec devoted exclusively to graduate-level research and training. The influence of our faculty and students extends around the world. In partnership with the community and with industry, we are proud to contribute to the development of society through our discoveries and through the training we provide to a new generation of scientific, social, and technological innovators.

**SOURCE**

Stéphanie Thibault, Communications Advisor

INRS, 514-499-6612, stephanie.thibault@inrs.ca

Institut national de la recherche scientifique - INRS

## Related Quantum Computing Articles from Brightsurf:

Bringing a power tool from math into quantum computing

The Fourier transform is a mathematical operation essential to virtually all fields of physics and engineering.

New detector breakthrough pushes boundaries of quantum computing

A new paper published in Nature shows potential for graphene bolometers to become a game-changer for quantum technology

A molecular approach to quantum computing

Molecules in quantum superposition could help in the development of quantum computers.

Cosmic rays may soon stymie quantum computing

Infinitesimally low levels of radiation, such as from incoming cosmic rays, may soon stymie progress in quantum computing.

UVA pioneers study of genetic diseases with quantum computing

Scientists are harnessing the mind-bending potential of quantum computers to help us understand genetic diseases - even before quantum computers are a thing.

New method predicts spin dynamics of materials for quantum computing

Researchers at UC Santa Cruz have developed a theoretical foundation and new computational tools for predicting a material's spin dynamics, a key property for building solid-state quantum computing platforms and other applications of spintronics.

Speeding-up quantum computing using giant atomic ions

An international team of researchers have found a new way to speed up quantum computing that could pave the way for huge leaps forward in computer processing power.

Boson particles discovery provides insights for quantum computing

Researchers working on a U.S. Army project discovered a key insight for the development of quantum devices and quantum computers.

In leap for quantum computing, silicon quantum bits establish a long-distance relationship

In an important step forward in the quest to build a quantum computer using silicon-based hardware, researchers at Princeton have succeeded in making possible the exchange of information between two qubits located relatively far apart -- about the length of a grain of rice, which is a considerable distance on a computer chip.

Diversity may be key to reducing errors in quantum computing

In quantum computing, as in team building, a little diversity can help get the job done better, computer scientists have discovered.

Read More: Quantum Computing News and Quantum Computing Current Events

The Fourier transform is a mathematical operation essential to virtually all fields of physics and engineering.

New detector breakthrough pushes boundaries of quantum computing

A new paper published in Nature shows potential for graphene bolometers to become a game-changer for quantum technology

A molecular approach to quantum computing

Molecules in quantum superposition could help in the development of quantum computers.

Cosmic rays may soon stymie quantum computing

Infinitesimally low levels of radiation, such as from incoming cosmic rays, may soon stymie progress in quantum computing.

UVA pioneers study of genetic diseases with quantum computing

Scientists are harnessing the mind-bending potential of quantum computers to help us understand genetic diseases - even before quantum computers are a thing.

New method predicts spin dynamics of materials for quantum computing

Researchers at UC Santa Cruz have developed a theoretical foundation and new computational tools for predicting a material's spin dynamics, a key property for building solid-state quantum computing platforms and other applications of spintronics.

Speeding-up quantum computing using giant atomic ions

An international team of researchers have found a new way to speed up quantum computing that could pave the way for huge leaps forward in computer processing power.

Boson particles discovery provides insights for quantum computing

Researchers working on a U.S. Army project discovered a key insight for the development of quantum devices and quantum computers.

In leap for quantum computing, silicon quantum bits establish a long-distance relationship

In an important step forward in the quest to build a quantum computer using silicon-based hardware, researchers at Princeton have succeeded in making possible the exchange of information between two qubits located relatively far apart -- about the length of a grain of rice, which is a considerable distance on a computer chip.

Diversity may be key to reducing errors in quantum computing

In quantum computing, as in team building, a little diversity can help get the job done better, computer scientists have discovered.

Read More: Quantum Computing News and Quantum Computing Current Events

Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.