A variety of different approaches to the production, manipulation and reading out of qubits is currently being pursued. These approaches share in common the very great and highly specialized technical effort they still require. Typical basic conditions include for example temperatures close to absolute zero and high degrees of vacuum – both of which present substantial challenges in everyday applications.

In order to rectify the error-proneness of physical qubits, they can be combined to form ensembles and can thus be used in more complex calculations. However, depending on quality, anywhere from several dozen to 10,000 or even more physical qubits are needed to make a single error-corrected logical qubit. This is at the heart of the major challenge in developing the respective approaches.

The following tabs explain three strategies for making qubits: Ion trap qubits, spin-based qubits and superconducting qubits.

In ion traps, lasers and microwaves put charged particles into precisely defined quantum-mechanical states. These states last longer and are easier to control than is the case with the other qubit approaches.

Comparably speaking, the ion trap approach has already made great progress. At its Villach site, Infineon is working together in particular with the University of Innsbruck, the Innsbruck start-up AQT and ETH Zurich.

Here the focus is on the use of industrial manufacturing methods and scalable architectures to realize highly scaled quantum processors. A particular focus is on developing reliable high-performance quantum CCD implementations (CCD stand for "Charge-Coupled Device") in which shuttling operations move ions between specialized processor zones. Infineon technology demonstrators with sufficient storage capacity for 18 individual ions have already shown for the first time the parallel movement of two ion arrays. They function at temperatures of approximately 10 Kelvin, i.e. around -263 degrees Celsius, and can be realized with comparatively little effort.

You'll find more detailed descriptions on the Infineon ion trap page. 

Superconduction refers to a state in which electricity flows through a conductor with no resistance whatsoever. In the case of many superconducting materials however this is only possible at very low temperatures close to absolute zero. Thanks to modern cryostats, which are essentially very powerful refrigerators, such temperatures can in the meantime be achieved with a reasonable amount of effort. Superconductors can be used to build circuits which behave quite similarly to atoms. The states of these artificial atoms can then be manipulated and read out electrically using microwaves. Superconducting qubits recently earned a certain reputation: They were the first technological platform on which the speed advantages of quantum computers could demonstrated in an experiment (based on a highly academic objective).

At its Munich and Regensburg sites in particular, Infineon is working together with the Walther Meißner Institute (WMI) of the Bavarian Academy of Sciences and Humanities, and the Finnish startup IQM, among others, to use superconducting circuits for quantum computing.

Silicon, at the most widely used starter material in semiconductor technologies, is highly familiar and easy to manage. Together with germanium, another semiconductor, structures can be created which catch individual electrons or their counterparts, referred to as holes, and use them as qubits.

Infineon Dresden is focusing on spin qubits in this kind of silicon/silicon-germanium heterostructure; these qubits are robust and fast and provide excellent scaling potentials. The principle entails what is referred to as a quantum dot, in which appropriate fence electrodes are used to "round up" a two-dimensional sea of electrons until ultimately only one single electron is left. The spin of this individual electron is a natural quantum system in which the direction of spin represents the information carried by the qubit.

In Dresden Infineon is working together primarily with RWTH Aachen University, the Leibniz Institute IHP Innovations for High Performance Microelectronics IHP and the Fraunhofer Institute for Photonic Microsystems (IPMS).

Quantum computers make previously impossible tasks possible. They provide access to levels of computing power which could never before be attained.

The smallest unit of information in the classic computer world is a bit. A bit can have either of two states or values. The smallest unit of information in quantum computing is the qubit, which can assume both the states 0 and 1 at the same time. This overlap of the states 0 and 1 is referred to as superposition. 

A salient example is a coin spinning on its edge: A classic bit corresponds to the two sides of the coin, heads and tails. In the case of a qubit, our coin is spinning so that an observer would be able to see heads, tails, and all the intermediate images as the coin turns.

The special ability of qubits to assume multiple states simultaneously results in incredible computing speed: Calculations are no longer executed sequentially, but rather can be performed simultaneously.

The superposition of many different states is not only the advantage of qubits, it's also the challenge: In order to use qubits in calculations, it has to be possible to precisely influence the qubits and to read out the qubits. At the same time it has to be possible to shield qubits from the outside world as well as possible, since otherwise the qubits can change their states very easily. It sounds a bit like Squaring the Circle.

Another challenge is being able to use the parallelism of the qubit states for general calculations. As yet there are no operating systems or programming languages which can make it easy to use the computing power of quantum computers for general tasks. Until now, only initial rudimentary quantum computers and the associated special software have been developed for individual highly specific and precisely delineated assignments.

Several quantum computers already exist. However, they are as yet too complicated to operate, are not particularly powerful, are rather defect-prone and are actually only viable for academic purposes. The physical qubits they use in the two-digit and soon probably low three-digit range cannot yet provide the desired leap in performance. Estimates vary as to when quantum computers will go into widespread use. Experts expect this to be the case for general, practically-oriented applications towards the end of this decade. However, use in more specific application cases appears to be probable before that point in time.

From the very beginning, Infineon's contribution to developing quantum computers has supported the successful commercialization of this revolutionary technology. Infineon wants to help lead quantum computing from the realm of fundamental research into the world of application and economic success. This is why Infineon, as a founding member of QUTAC, is active in the consortium of leading German companies working to raise quantum computing to the level of wide-scale industrial application.

Infineon places particular emphasis on the industrial scalability of this technology. Outstanding scientists and engineers work at Infineon. Their expertise in chip design, materials, production and hardware-oriented software gives the company essential know-how capable of driving the development of quantum computing a decisive step forward.

If quantum technology results in real, unique benefits for applications, the development of quantum computers could become a true success story. There are plenty of examples of tasks which are highly difficult or impossible to solve with classic computers. Here are just a few:

• Simulation of chemical reactions at the atomic and molecular levels
• Targeted design of medications
• Development of innovative materials, for example for lightweight design, catalysts and battery electrodes
• Close to real-time analysis of complex data, for example for Machine Learning
• Optimization of complex logistics processes
• Analysis of financial processes

Infineon itself constantly works to optimize capacity utilization in its production and logistics processes, with the objective of best possible fulfillment of customer demands. Much data and information flow into this optimization process. The considerable power of quantum computing could be used to evaluate more data from processes, from sensors and actuators together with other basic parameters and thus further advance optimization.

The computing power of future quantum computers will make it possible to break the encryption systems which are conventional today. Keeping systems and data safe even in the age of quantum computing will require quantum-secure cryptography methods which have to be developed today. Infineon is one of the pioneers in actively driving post-quantum cryptography ahea. For more information please click here.