Quantum technology for beginners

One of the best-known applications of the second generation is the quantum computer, which works on the basis of quantum physical states and therefore offers considerable speed advantages over digital computers, for example when searching large databases or solving complex mathematical problems. Quantum computers also enable large numbers to be broken down quickly into prime numbers (factorization). This is important for data encryption, for example.

Quantum computers are likely to open up completely new perspectives, particularly in the field of complex simulations, in which many influencing factors often overlap and have to be calculated simultaneously. Possible applications include more efficient traffic planning for urban infrastructures and more precise predictions of chemical processes, seismic activity or weather phenomena. The latter could provide fruitful impetus, particularly in the analysis and management of climate change or in the forecasting of severe natural disasters.

Nevertheless, the quantum computer also poses a challenge for our IT securitysecurity. This is because the encryption systems commonly used today, which are based on digital technologies, would be easy for a quantum computer to crack. Companies are faced with the task of carrying out appropriate risk analyses and, if necessary, switching to encryption technologies that can cope with the computing power of a quantum computer. Conversely, quantum cryptography should make it possible to implement tap-proof communication systems in the foreseeable future.

Almost more important for quantum computing than hardware development is the provision of algorithms and software solutions that effectively utilize the special properties of quantum technology for new applications. Since attributes of quantum computers "can also be simulated to a certain extent [...] with conventional digital computers", existing quantum computers are not even absolutely necessary for this. [2] This means that quantum applications can already be developed before the corresponding quantum computer hardware is actually available. Companies such as BMW and VW are already investigating the possibilities of using already available quantum computers to optimize production processes, for example in the control of welding robots [3] or in the optimization of traffic flow in large cities. [4]

Quantum technology is likely to usher in a new era for data security . Instead of zeros and ones, much more complex, entangled quantum states ensure the security of data transmissions in encryption. Concrete quantum states indicate unauthorized data access. Quantum cryptography therefore enables encryption technologies that are based on physical rather than mathematical principles. The key exchange is based on the exchange of photons via fiber optic networks, in a straight line through the air or via satellites. Applications are of interest to governments, banks and all sectors that rely on maximum data security. Quantum cryptography is likely to replace conventional digital encryption methods in sensitive areas in the medium term. Companies are already working on post-quantum cryptography to make existing data inaccessible to quantum computers.

Quantum states are particularly sensitive to factors such as vibrations, shocks, temperature fluctuations, electric, magnetic and gravitational fields or changes in speed - and therefore make it possible to measure these parameters with particular accuracy. For example, quantum effect-based sensors will make it possible to explore what is going on beneath the earth's surface - from water deposits and mineral resources to seismic activity. Quantum-based sensors provide precise information about the composition of the ground and can therefore speed up construction projects, for example. Another potential application in the automotive sector is the development of high-precision sensors for autonomous driving.

The precise time measurement of an atomic clock has already become an integral part of our everyday lives. It is required to synchronize global data and communication networks with each other or to enable precise location determination by satellite navigation systems such as GPS or Galileo. Thanks to advances in quantum technology, high-precision, much more compact optical clocks should be feasible in the future, which, with their short clock frequency, will enable GPS systems to determine location with millimeter precision, for example.

In the healthcare sector, quantum-based systems have already revolutionized imaging for medical applications with magnetic resonance imaging in the first generation. Quantum-based sensors of the second generation allow, among other things, a more precise and much gentler measurement of brain waves through magnetoencephalography (MEG) or heart waves through magnetocardiography (MKG). [5] In addition, it should be possible in the foreseeable future to use STED (stimulated emission depletion) microscopy to generate images with a resolution that is far superior to conventional microscopes. [6] In quantum ghost imaging, entangled photons are used to separate the illumination of a measurement object from the actual measurement process. However, the method, which is intended to enable high-precision measurements, has hardly been tested experimentally to date. [7]