Step toward quantum computers: Using commercial photonic components

The research has been published in the journal Laser and Photonics Reviews.

This is the first model published anywhere in the world that describes the full operation in quantum regime of integrated optical modulators, which are devices used to modulate light with information. Such devices make it possible to achieve speeds of around 100 Gb/s.

José Capmany, who is the director of the Universitat Politècnica de València's ITEAM Institute and one of the authors of this work, explains that these components, which are nowadays available commercially and used in broadband telecommunications, may be applied in the future to the production of logical systems and quantum computers by exploiting the properties unveiled in this study. These properties are related to the possibility of generating entangled states of light and being able to process them in a way similar to the logic gates in digital electronics.

"The ability to integrate several of these components into an optical chip opens the door to designing more complex, less expensive circuits by taking advantage of the economies of scale provided by photonic integration," says Capmany.

Together with Professor Capmany, this work has been developed by Carlos R. Pousa Fernández, a researcher at the Universitat Miguel Hernández d'Elx's Department of Communications Engineering. They presented their findings at the final meeting of the CONSOLIDER-INGENIO Quantum Information Technologies (QOIT) project, held last week in Barcelona.

On quantum computers

The work of these UPV and UMH researchers is a step forward in the study and the development of quantum communication and quantum computers, which will be a big revolution in the field of telecommunications.

"We are still at an early stage. The first quantum computers will appear in about 15 years. They will open up an entirely new field by multiplying the capacity to store and process information in very small sizes. Currently, one of the obstacles to their development is that the demonstrations that have been made were based on extremely bulky assemblies which entailed conditions that can only be reproduced in controlled laboratory environments," adds José Capmany.

On the capabilities of quantum computing, the director of the UPV's ITEAM explains that it will allow for much faster calculations and for processing speeds that will make possible the resolution of problems whose complexity makes them unapproachable with today's classical computers. Its uses are many, from massive simulations in meteorology, climate, chemistry, genetics, etc., to new quantum security systems, which will generate completely indecipherable encrypted messages.