The Quantum Leap

When it comes to the future, Angela Merkel can be impatient. This was evident at an exhibition during the federal government's recent digital summit. Following the rather extensive remarks by the head of the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena, the federal chancellor summed up with her characteristic matter-of-factness, “So it's going to a take a while before these things become available.”

“These things” represent the future of computer technology, based on the laws of quantum physics. Aa a physicist herself, Angela Merkel knows this very well. She takes one of them loosely in her hand. Within the foreseeable future, a quantum source within the gold box which she holds will generate entangled light particles that can be used to generate “unhackable” encryption – and thus also a contribution to the “data sovereignty” of the German government. The prerequisites for this presentation, as described in the briefing memo, include “a large monitor, an electrical outlet and six square meters.”

The prerequisites for a breakthrough in quantum computing include a strong will, access to international research and a great deal of money and patience. Above all, however, quantum computing requires us to say goodbye to a few fondly held certainties. And even Albert Einstein had difficulty with that requirement. He once called quantum physics, which also provides the basis for quantum computing, “spooky.” Even today, many people still find it spooky that the laws of physics – which have formed the basis of our thinking since Isaac Newton's “Principia Mathematica” (1687) and were previously held to be immutable –  should no longer apply. Simply put: There's a rock on the ground. If I kick it, it will fly for a certain distance and then land back on the ground. The stone always occupies an exact position in space, but that position can change over time. It's inconceivable for the rock to be in two places at once.

Or is it? That's the premise of quantum physics. At least when it comes to smaller particles than rocks, like an electron for example.  It does not exist in a particular state, in a place that can only change with the passage of time. It always exists in a cloud of probability. Everything in our world, every particle, a multitude of which make up every larger thing, remains blurry and imprecise. Unless someone is watching. No one knows whether two people in a closed room are sitting apart from one another on separate chairs or embracing each other in the center of the room. Unless they open the door and look inside.

The particle world of quantum physics therefore operates very differently from the macroscopic world we know as human beings. This concept was and is a provocation for many people, not just for Albert Einstein. But it is the future of computer technology.

Quantum: Clash of the titans

Which brings us to the threshold of the wonderful world of quantum computing. A technology that is making tremendous progress at the moment. Not only does it enable computers to achieve completely new and gigantic computing power, but it can also completely revamp the architecture and applications of today's Internet – especially in connection with the second technological revolution, the steady progress of artificial intelligence.

All over the world, companies and scientists are currently building new types of quantum computer. Google's “Sycamore,” which in late 2019 was one of the biggest breakthroughs in the world of computer research in decades, takes just 200 seconds to perform a task that would take the world's best traditional supercomputer, built by IBM a while back, 10,000 years to complete. For its part, IBM has a supercomputer of its own that can now do similar things, and is developing a second one that should go into operation within weeks in Ehningen near Stuttgart. And Microsoft, the Canadian D-Wave Group, Amazon, Alibaba, several Chinese and Japanese technology companies, and hundreds of top research institutes around the world are all working on similar projects.

Late last year a Chinese research team announced a breakthrough. The Chinese quantum computer is said to be able to solve some computing tasks ten billion times faster than Google's prototype. Is this the beginning of a new competition among the developed nations? Yes indeed!

China's government is building a ten-billion-dollar National Laboratory for Quantum Computing Sciences as part of a strategic push in this field. In the USA, the government has allocated a billion dollars for research in the areas of artificial intelligence and quantum computing. In the European Union, the EU commission launched the “Quantum Technologies Flagship” in 2018 with a budget of more than a billion euros. The militaristic language is another indication of how hard the battle is being fought in this field. It's all about “quantum supremacy.”

The goal is to make quantum computers widely feasible, i.e. marketable. Whoever achieves that holds the keys to the gold mine of the future. It won't happen with a single breakthrough. Sundar Pichai, CEO of Alphabet and Google, says, “It definitely won't be easy.” It will take political will and a lot of money and commitment to make progress. “This will be an effort over several decades,” Pichai says. “But the next three to five years will be interesting, when we make the infrastructures available so developers all over the world can work with them.”

More than “50 Shades of Grey”

It is only becoming possible at all because IT and quantum physics are merging. Instead of letting computers calculate in bits, as has been the case in the past, modern quantum computers use QuBits, small particles of light that are so elastic they can assume not only the states 0 and 1, but also any flexible state in between. In scientific terms, “quantum” refers to the smallest possible physical quantity. For example, a particle like a photon is not divisible.

Assuming you are able to steer them precisely, this permanent whirling of the smallest bits of information in a computer makes it possible to perform a huge number of calculations simultaneously – because the QuBits can take on constantly changing properties as they float unstably in space.

This makes the basic certainties of the previous computer revolution obsolete. Up to now, technological change adhered to the principle of “the faster the better.” Every few months, researchers enhanced the speed with which computers could perform tasks, and progress has continued apace since the 1950s. But speed is two-dimensional; it is defined as the time it takes a particle – in this case, a bit – to get from A to B. Quantum computing makes progress three-dimensional; QuBits not only decrease the distance between A and B but also make it possible to plan a route covering C, D, E and so on. Progress is no longer limited to a linear playing field – it's now a space. A space where nothing is logical but everything is possible.

This can certainly be seen metaphorically. “Conventional computers work the way we flip a coin,” says American journalist and New York Times columnist Tom Friedman. “It's always heads or tails. With quantum computers, the coin spins endlessly on the table, with both sides always present.” Former IBM boss Ginni Rometty adds, “Quantum is the physical variant of ‘shades of gray’” – and there are many more than 50. For Sundar Pichai, quantum computing even represents a return to nature, which in many respects works like a quantum computer – not with the binary distinction between 0 and 1, but with many intermediate states. “Quantum will enable us to understand and simulate the world more deeply,” Pichai says.

The quantum internet

The development of even individual quantum computers opens up unimagined horizons of knowledge. But who says that these supercomputers have to work in isolation? When they are networked with each other, as the Internet has already done with “normal” computers, their advantages will really come to the forefront.

Technologically, this development is also still relatively in its infancy, but the progress made in recent months has been immense. In principle, the idea behind a quantum web is the ability, thanks to quantum physical phenomena, to transmit data securely as pieces of light. This means that data no longer has to travel linearly from the sender to the receiver via many intermediate stations – and be subjected to the limited bandwidth of today's Internet. Instead, in extremely simplified terms, computers beam it directly from the sender to the receiver as light particles converted into commands. The information itself does not travel at all, just laser photons that transport commands to the receiver via fiber-optic networks, by submarine cable or even through the air. For a long time, this was a theoretical gimmick; researchers succeeded in reliably communicating between two partners, but that was all.

The breakthrough came late in 2020, when Google research Siddarth Joshi and his team managed to do it all with a network of eight computers absolutely securely and particularly quickly. Since then, many no longer see the quantum web as a utopian vision but as a real future.

“Some time ago,” said the now-deceased U.S. physicist Jonathan Dowling last year, “I would have bet that a network of quantum computers wouldn't come for another 100 years. Meanwhile, I'd say in 10 years we'll have an infrastructure we can call a quantum web.” One reason progress might be achieved so quickly is because the quantum web doesn't have to replace the current Internet, but will complement it, piece by piece. Quantum physicist Shohini Ghose says, “In the future of the Internet it won't be that the entire regular Internet somehow disappears and everything will be quantum. It will probably be a hybrid, an enhanced version of what we have today.” In the beginning, users will benefit without even noticing it.

Physicist Jonathan Dowling prophesied: The quantum internet will be introduced in three steps. “In Quantum Internet 1.0 [...] the network does one thing: It deploys quantum cryptography nationwide to secure its data.” This phase has already been running in China since 2016. The country wants to switch all its governmental and financial communication to it by 2025. “Quantum Internet 2.0,” according to Dowling, “will expand this network by enabling more participants than previously to communicate with one another using this kind of encryption.” In this phase, the conventional Internet will still be needed, because most users will still be logging on using conventional devices. “Finally however, in the quantum web 3.0, the traditional Internet will disappear entirely,” Dowling assumes.

That would indeed be the revolution. Not only because Europe has so far played on a par with the USA and China in this technology, despite Google's and IBM's publicly visible successes in some fields. But also because the quantum web could be the innovation that brings together many of the other technologies and hopes of the network economy: machine learning, artificial intelligence, the Internet of Things, secure communication – all of these things might only become really practical with a quantum web. “The quantum web,” said Fraunhofer President Reimund Neugebauer, “is revolutionary in at least two areas. Quantum communication becomes much more secure, and quantum imaging makes it possible to use sensors in ways that were not feasible before.” These sensors operate with previously unimaginable precision. They can identify diseases before the first symptoms even show up. They let the driver of an autonomous car know if someone outside their field of vision around the corner is currently on a collision course.

This sounds a bit “spooky” again, to use Einstein's word – as if the sensor had telepathic abilities. But it just has abilities that result from the principles of quantum physics. And they don't really fit in with how we see the macroscopic world – or the Internet.

The web will be stronger

Up to now, digital computers have calculated in a very rational and organized way; they're the Prussians of the electrical world. In accordance with previously defined rules, they manage even the largest amounts of work by stoically dividing it into tasks, putting it in an order, and making an either-or decision for each task, one after the other. Once a computer has decided on 0 or 1, it moves on to the next task. This is very rational. But also very slow.

Eventually there will be a decision backlog. We can observe this phenomenon in the Internet of Things. If we want more and more devices to communicate with each other intelligently and autonomously, the network will eventually comprise trillions of access points. This can hardly be controlled with the current network architecture. But the quantum web can handle it. A car driving autonomously in traffic can't just wait until the network deigns to provide it with the information whether it should turn left or right, brake or accelerate. And it's hard to imagine what would happen if the system were hacked. In the quantum web the first is secure, the second impossible.

As is to be expected, the industry is euphoric. “I can say that in the year since we launched our quantum computing offer Amazon Braket, we've seen enormous interest, particularly from larger companies,” said Amazon's chief technology officer Werner Vogels early this year in the FAZ newspaper. “Biosciences, pharma, financial services – they are all looking into it and have some idea of what quantum computing could do for them.” And Canadian quantum physicist Shohini Ghose adds, “There are so many obvious applications.”

Quantum computers, once they are networked with one another, set in motion a self-reinforcing evolution. This is because of their absolute security. Previously, data encryption worked something like this: “When I want to send a message like ‘Hello,’” Ghose explains, “that ‘hello’ is converted into a series of zeros and ones. And the signal transmits this series of zeros and ones to a satellite in orbit, which then transmits this particular signal to my friend in Australia.” That friend knows that a ‘hello’ has arrived. The quantum internet, on the other hand, uses electromagnetic radio signals consisting of light waves. And these individual light waves have light particles called photons. The particles know about each other, as it were, which is why the process is also called teleportation. In the encrypted communication of the future, nothing will be transmitted or exchanged, but light particles will talk to each other. But they will only share their secret with those who are entitled to it.

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