### Quantum Computing

Quantum computing is the latest trend in the computing sector. For some years, large companies such as Google or IBM have been researching so-called quantum computers. Compared to the classical computer, a quantum computer is based on the fundamental principle of quantum mechanics. Quantum mechanics includes the theory of the smallest particles. This behavior is used by quantum computers to perform complex calculations in the shortest possible time.

Already in the 1980s, Richard Feynman postulated the future of the quantum computer: „If we want to simulate nature, we need a quantum computer“. Over the years that followed, quantum computer theory was constantly advancing. In the mid-1990s, Peter Shor outlined a quantum algorithm that can decompose any large number into its prime factors in a short time. The Shor-Algorithm – named after him – represents a direct threat to all existing RSA encryption techniques. At the beginning of the millennium, companies such as IBM or D-Wave began to build the first quantum computers. To date, D-Wave, IBM and Google are world leaders in the field of quantum computing and have first system architectures, which can already solve the first real world problems.

Manufacturers of quantum computers and the industry expect great benefits from quantum computers. These computational advantages are based on the so-called superposition principle. While classical bits can only assume a state (0 or 1), a qubit can be in both states at the same time (superposition principle). By connecting N bits in a classical computer, they can assume exactly one state (of 2 high N possible states). By contrast, quantum gates can accept these 2 high N states at the same time, thus solving complex problems much faster.

Adiabatic quantum computers, one manufacturer is D-Wave, can already control 2000 qubits stably. Gate-calculator models, such as Google or IBM calculators, can now successfully control 53 qubits. While D-Wave’s quantum annealer can only be used for certain problem classes, gate computers are much more flexible. Which computer architecture is the better depends entirely on the problem. Google announced in the fall of 2019, together with NASA, that they could solve a NP-hard problem, in which a conventional supercomputer would have needed 10,000 years, in just under 200 seconds using a quantum computer. IBM is critical of the statement by Google and countered that a supercomputer would have needed only 2.5 days (with proper configuration). Whether the proof of the so-called quantum supremacy has succeeded, is still pending.

FCE has been a consortium partner of the BMWI-funded PlanQK project since July 2019. PlanQK (Platform and Ecosystem for Quantum Assisted Artificial Intelligence) is an association of business enterprises and universities that will build a public-access platform for classical and quantum-based artificial intelligence algorithms within the next three years. FCE assists with the implementation of mathematical solution methods for complex problems, such as the Traveling-Salesman-Problem.

Furthermore, over the last two years, FCE has built some expertise in quantum computing and advises a wide range of companies. FCE holds quantum computing workshops and advises companies on specific issues.