Towards a hybrid technology that combines classical and quantum computing

A new step in the development of a hybrid technology that combines classical and quantum computing. The milestone comes after a team of researchers at the University of Bologna successfully ran a quantum optimisation algorithm on Fresnel, the first commercial neural atom quantum computer, developed by the French company PASQAL.

The project, coordinated by Professor Elisa Ercolessi, and personally supervised by Simone Tibaldi, a PhD student of the 'Augusto Righi' Department of Physics and Astronomy, was funded by IFAB and is the result of a collaboration with CINECA, INFN and Leithà-Unipol.

Unlike a classical bit-based computer, a quantum computer is composed of qubits (quantum bits), elementary quantum objects capable of exploiting phenomena specific to quantum mechanics, such as the superposition of states and entanglement. In the case of the quantum Fresnel machine, the elementary quantum objects used are atoms.

"Research in the world of quantum computing has accelerated dramatically over the past two decades and involves many universities and large companies around the world, because of the potential for huge computational and energy benefits that we are still struggling to accurately predict and estimate," explains Professor Ercolessi. “However, there are still major theoretical and technological challenges to operating a quantum computer.”

To address these challenges, the University of Bologna’s research team developed a model for a hybrid classical-quantum optimisation algorithm (Quantum Approximation Optimisation Algorithm), that synergistically uses quantum and classical resources to solve a typical complex combinatorial problem on a graph.

"The purpose of this work is twofold: refine the algorithm by adapting it to the experimental properties of a real quantum machine and demonstrate its correct operation on Fresnel," commented Simone Tibaldi. "The results we have obtained are part of a series of experiments which confirm that the use of a hybrid technology that combines classical and quantum computers is getting closer and more promising".