Quantum computing

Quantum computing looms large on the horizon

In January 2019, IBM unveiled the world’s first commercial – i.e. non-laboratory – quantum computer: the IBM Q System One. In 2021, the Q System One will be coming to Germany.
© IBM Research
In January 2019, IBM unveiled the world’s first commercial – i.e. non-laboratory – quantum computer: the IBM Q System One. In 2021, the Q System One will be coming to Germany.

Analysts at Morgan Stanley predict that the market for high-end quantum computers will reach 10 billion dollars by 2025, double what it is now. Alongside IBM and Google, there is also Microsoft, the Chinese Internet giant Alibaba and startups such as Novarion, Rigetti and D-Wave. Yet the various manufacturers rely on different physical principles for the realization of the quantum hardware. Scientists distinguish between universal quantum computers, which can perform arbitrary quantum algorithms, and quantum annealers, which are less complex, but limited to very specific tasks. Researchers at VW have been using a D-Wave quantum annealer since 2017 to better simulate traffic flows. And BMW is investigating whether quantum annealers can help optimize its production robots’ performance.

Universal quantum computers are technically very challenging to build and operate. What sets these computers apart is that their performance doubles in power with each added qubit, thereby increasing in exponential rather than in linear fashion. In other words, two qubits yields four possible combinations, three qubits eight, and so on. The quantity of qubits matters, but evenly important is the quality of qubit entanglement and its coherence time. The latter determines how long the quantum system remains stable enough to compute before noise masks the information. Most universal quantum computers, such as Google’s 72-qubit Bristlecone, only work under special laboratory conditions.

In January 2019, IBM unveiled the IBM Q System One, the world’s first commercially viable quantum computer – meaning that it works outside a lab. A consortium of seven Fraunhofer Institutes in Germany has been tasked to look into real-world applications for quantum computing as of 2021 in a bid to drive the advance of applied quantum science in the EU. “We want to find out just what kind of applications there are for quantum computing in industry and how to write the necessary algorithms and translate them for specific applications,” explains Hauswirth. The initiative also aims to keep entry barriers low by sharing insights with companies to fast-track the industry’s efforts to build a knowledge base in quantum computing.

There are still high hurdles to clear on the path to upscale the performance of available quantum computers. The priority now is to find ways of shielding the fragile quanta from ambient influences that interfere with the computing process. For example, qubits have to be cooled to a temperature approaching absolute zero – around minus 273 degrees Celsius, which is colder than outer space. They also require a vacuum and have to be shielded against electromagnetic radiation. Vibrations and parasitic effects of electromagnetic waves used to manipulate the qubits and read out the information they carry can also cause problems.

Solving complex problems

What kind of real problems can quantum computers solve? “In a few years from now, quantum computers will provide highly efficient means for prime factorization. That will leave current cryptographic systems vulnerable, which is why major research into post-quantum cryptography is underway,” says Hauswirth. Quantum computers will be able to tackle even more complex problems a few years down the road: “Today’s fintech, for example, has trouble managing billions of cash flows in parallel and in real time within the confines of a very tight regulatory girdle. Sequential processing is still prone to errors, but quantum computers would help get around this.”

Prof. Anita Schöbel is director of the Fraunhofer Institute for Industrial Mathematics ITWM in Kaiserslautern. She and Hauswirth are mainly responsible for quantum computing at Fraunhofer. Pointing to an application in the works at her institute, she says, “We’re working on projects that use stochastic partial differential equations such as the Fokker-Planck equations. These serve to develop lithium ion batteries and wind turbines, calculate granular flows and determine prices in quantitative finance. These equations can be converted into quantum mechanics equations for quantum computers to crunch the numbers, probably much faster.”

Applied quantum computing is clearly taking shape in the real world. Will we all have a quantum home computer or a quantum processor in our smartphones in a few years? “Quantum computers will only ever be able to solve very specific problems, so they won’t replace conventional computers. It’s likely that cloud-based models will prevail – that is, quantum computing as a service (QCaaS). We’ll probably also see hybrids of quantum computing and conventional high-performance computing,” says Hauswirth.

When will the quantum computer arrive?

Prof. Manfred Hauswirth, director of the Fraunhofer FOKUS.
© Fraunhofer FOKUS/Philipp Plum
Prof. Manfred Hauswirth, director of the Fraunhofer FOKUS.

Three questions for Prof. Manfred Hauswirth, Fraunhofer FOKUS, on the quantum computer initiative with IBM


What is this project all about?

In partnership with IBM, we are going to install Europe’s first commercial quantum computer at a location in Germany. The aim is to develop applied quantum computing solutions for a range of fields and assess their viability. We would like to see companies of all sizes involved in this project.

Why does this matter?

It is early days yet for applied research in quantum computing. We need to define quantum algorithms and then convert them for easy use in applications programming. That requires expertise on the part of industry, so we want to fast-track efforts to build a knowledge base here in Germany. This initiative will also enable us to pursue quantum computing under full data sovereignty according to European law, without being dependent on large Internet corporations from overseas.

When do you expect to see the first results?

A quantum computer is to be installed in Germany in 2021. But even optimistic forecasts suggest it’s going to take another 10 to 20 years before businesses can use quantum computers.

From supercomputer to superinternet

Research teams around the world are working on the most efficient way to couple together multiple supercomputers using quantum information to create a quantum internet. At QuTech in Delft, a number of partners, among them the Fraunhofer Institute for Laser Technology ILT, are currently working on a highly ambitious project. By 2022, they hope to have built the world’s first quantum internet demonstrator in the Netherlands with the aim of achieving lasting entanglement of qubits over long distances. Nodes at four locations will be connected together via fibre-optic cable. This will enable greater computing capacity, as well as completely new applications, such as blind quantum computing, where computations are performed securely, privately and anonymously on quantum computers in the cloud. According to Florian Elsen, coordinator for quantum technology at Fraunhofer ILT in Aachen, the big challenge lies in “transmitting single, fragile qubits through a fibre-optic cable as losslessly as possible. To achieve this, we carry out frequency conversion, meaning that we modify the wavelength of single photons without changing other significant properties.” Once you have a quantum internet, it is not much of a leap to quantum communication.

How does a quantum computer work?

© IBM Research

A conventional computer works with bits; a quantum computer with qubits. Like bits, qubits can have a value of 0 or 1. Unlike bits, they occupy a superposition of overlapping quantum states, so they can also have any combination of the two. A qubit does not take on a definite value until it is measured. Adding one qubit doubles the system’s performance so that 50 qubits, for example, would yield 2 to the power of 50 (250) possible combinations. This way, big problems and complex tasks are computed in parallel rather than in linear fashion.


David Di Vincenzo’s* five criteria for a quantum computer

1. A scalable physical system with well characterized qubit
2. The ability to initialize the state of the qubits to a simple fiducial state
3. A "universal" set of quantum gates
4. A qubit-specific measurement capability
5. Long relevant decoherence times

*Pioneer of quantum information science and professor of theoretical physics at RWTH Aachen