Trying to solve difficult computing problems efficiently is a long-standing endeavour. Computers with increasingly powerful computing capabilities are being developed every year. New types of quantum computers use quantum mechanics as their operating system. These systems promise to revolutionise many computational problems that are important for society and industry, but are too complex even for today's best supercomputers. Such problems include the simulation of chemical bonds, the discovery of new drugs, or the efficient solution of some NP problems, a complexity class of mathematical decision problems.

Researchers in physics, mathematics, computer science, chemistry and engineering are working to develop the most powerful quantum computers. However, none of these devices has yet outperformed classical computers in practical applications. For example, quantum computers have a theoretical advantage in breaking large numbers for encryption, but in practice would require millions of contiguously controlled physical qubits (the smallest possible piece of information) and their manipulation – a scale far beyond today's quantum computing technology.

Nevertheless, in recent years, famous proof-of-concept experiments have shown a quantum advantage over the best classical supercomputers, but only for tasks without practical application. This raises the question: Can today's quantum devices outperform classical supercomputers at a meaningful task? Currently, quantum chemistry is considered by the quantum computing community to be one of the most promising areas in which quantum computers could outperform classical computers in the coming years.

To achieve this, both the theory of quantum computing and the quantum devices need to be improved. One way to build a scalable and robust quantum computer is to shift the focus from a single quantum device to a collection of quantum devices interacting coherently through a quantum network – also known as a quantum internet. Quantum networks are seen as the most promising resource for scaling quantum computing, with many small, high-precision quantum computers linked together to achieve a quantum advantage. Despite all the experimental developments, there is still a lack of theoretical background on how and for what tasks the distributed quantum computing platform can be used.

This is where the research of Professor Mariami Gachechiladze from the Department of Computer Science at TU Darmstadt comes in: On the one hand, we are advancing the applications of quantum chemistry using quantum computation, and on the other hand, we are exploring the novelties and limits when quantum information processing is performed in a quantum network instead of on a single device," explains Gachechiladze. Until now, these two areas have been considered independently of each other, as they require completely different skills and training to address their respective challenges.