Why is quantum computing potentially a better fit for weather forecasting than classical computers?

He is leading a project to develop a fully scalable quantum computer. The project is part of the EU’s €1 billion, 10-year Quantum Flagship initiative to kickstart a competitive European industry in quantum technologies.

What is a quantum computer and how does it differ from classical computers?

‘The big difference compared to a classical computer is that a quantum computer is following a different rule set. It’s not using zeros and ones like classical computers are – bits and bytes – but it is actually able to work with something called qubits.

‘Qubits are quantum bits, and have the special property that at the same time they can be zero and one. The classical computer can only be – like a light switch – either on or off, and the quantum bits can be on and off at the same time.’

What’s the effect of that?

‘This superposition essentially allows it to do things that a classical computer can’t do. Because it’s in many states at the same time, in simplified terms, it allows you to probe many possibilities at the same time. (For example), if you are working in finance and you want to say which portfolio has the largest profit, you need to take many, many different cases into account and then find the best one. And this is something that a quantum computer, because it essentially allows you to calculate many things at the same time, is notably more suitable for.

‘(Another) prominent example is energy material design. Think about the power line you get at home.  You have friction – ohmic resistance – in the cable. That’s why an electric motor or your hairdryer gets warm. Quite a bit of a power is lost from the power plant before it gets to your house. Can we come up with a new material, which doesn’t have ohmic resistance, so we don’t have (energy) losses in the cable? The inherent properties of how friction in materials work, that’s partially governed by quantum mechanics. And a quantum computer (finds it) easy to follow the rules of quantum.

‘It allows you to do material design and check what are good candidates for materials that wouldn’t have, say, ohmic resistance, and suddenly we save a couple of percent on global energy loss from the power plants to the consumer.’

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'All of quantum physics was developed 100 years ago in Europe. This is something that we excel at.'

Dr Thomas Monz, University of Innsbruck, Austria

Where are we now in the development of quantum computers?

‘There are currently several proof of concept implementations. (For example) companies are working in the finance area on portfolio optimisation. Certain companies are working towards chemistry – one prominent example is how to generate fertiliser.

‘(But) I think the key question is, regardless of what quantum computer we actually talk about, give me one case where it will outperform the best classical computer worldwide.

‘And the timescale on that, I would guess it’s in the order of another year.’

One of the big challenges is going to be writing algorithms to program quantum computers. Where are we with that?

‘There are a couple of (algorithms) already, but obviously you want to have more.

‘Everything started with Shor’s algorithm (which can find the factors of prime numbers on which today’s encryption systems are based). This was an algorithm that could convince (government) agencies to look into quantum computing, because it can break some of the most prominent encryption methods that we currently use. That was the starting point about two decades ago.

‘In the meantime, people have been working on (algorithms for) optimisation calculations. If you want to optimise a (financial) portfolio or make sure no-one gets stuck in a traffic jam – mathematically they are all very similar.’

Will our use of quantum computers depend on the algorithms that we’re able to develop?

‘Sure. Think about your smartphone. Your smartphone is a computer and depending on which app you load, it can be something where you send out a message or you hear some music. A quantum computer is also fully programmable. The more algorithms we have, the more apps we can build with those algorithms, and then you want to have your quantum app store.’

Is it fair to say that we won’t have quantum computers at home in the future because they’re something very specialised?

‘Partially. Say there is a quantum computer available right now, would you buy one? If you say, “I mainly write emails, watch videos and store my pictures,” you wouldn’t need a quantum computer – not for the moment.

‘(But) think about your classic computer. For graphics, it has a graphics card. It’s likely there will be a quantum co-processor in the long-run. It will be an add-on to your classical computer to give you some additional capabilities for special computing (or something such as secure communication).

‘(Or) it could be that there are quantum computers available and you can have access to them via a simple cloud interface.’

You run a project called AQTION, which is trying to build a quantum computer. Can you tell us a bit about it?

‘IBM, Intel and Google are building on solid-state semiconductors (used to make computer chips) whereas we are using single atoms. In solid-state systems, you start with a lump of material and try to control it so it becomes quantum. Our approach is the opposite. We start with an atom, which is already quantum, and look at how to control it. We already have the quantum properties, so we only – only in quotation marks – have to focus on the classical (engineering) part of it.

‘Another aspect is that most of these (solid-state) computers are built in a lab environment. (Our quantum computer) is meant to operate in an office environment. If the air conditioning breaks, it still ought to work. If you want to ship it to a partner, you disassemble it, put the boxes into wooden crates, you ship that, you assemble it, and it ought to work. Rather than this once-in-a-lifetime prototype that only exists in one lab.’

So the question is still open about the best way to build a quantum computer?

‘Yes. I would argue there are probably five or six approaches. The two most promising for the moment are trapped ions – that is what we pursue – and superconducting systems.’

We always hear about the private companies that are driving forward quantum computing. What effect will the EU’s Quantum Flagship have?

‘Intel, IBM, Google all pursue a technology (to build quantum computers) that’s close to their hearts. If you have a hammer, everything looks like a nail; if you are in the semiconductor industry you want to address every new potential application with semiconductor technology. That’s what they do.

‘I think what the funding from the EU allows us to do is to compete with these entities because there are not that many companies in Europe (pursuing quantum technologies). The second part is, maybe you want to have a different tool using a new technology (not just semiconductors). So if one technology might be a dead end in the long run, we have in Europe a plan B and a plan C because we don’t put everything into one bucket.

‘The Flagship is looking not only at computing, but also clocks, sensors, communications. It has a long-term vision of quantum computing as well.’

Where does Europe stand in the global race on quantum technologies?

‘Think about Schrödinger, Einstein – all of quantum physics was developed 100 years ago in Europe. This is something that we excel at. We have invested in fundamental research for essentially the last 100 years, and now that there is the chance of turning research into technology and applications, we shouldn’t miss that train. We have a very good chance of making that work.’

The research in this article is funded by the EU. If you liked this article, please consider sharing it on social media.

This interview has been edited for clarity and length.

What is quantum computing?

Quantum computing is one of those technologies that futurists often joke is always a couple of decades away. It’s true that it will be a decade or two before the technology reaches maturity (in widespread use in business), but there are already opportunities for some organisations to gain early experience and benefit today. But to do that, you need a basic understanding of what quantum computing is.

The ‘quantum’ difference

Quantum computing is completely different from today’s ubiquitous digital computers. It exploits the properties of quantum physics (the physics of subatomic particles) to perform calculations and simulations that would not be practical on a non-quantum machine.

The power of the quantum computer comes from the fact that it’s not limited to binary bits (the ones and zeros of traditional computer processors). Instead, it uses quantum bits, or qubits, that can represent a one, a zero, or both at once – a ‘superposition state’ that encompasses a near infinite spectrum of probabilities.

This means quantum computers approach problems very differently – essentially attacking them concurrently rather than sequentially. They manipulate the properties of quantum entangled qubits to simultaneously try a vast number of solutions, rather than trying each in turn. This translates to dramatic increases in speed when solving certain classes of problem.

First generation quantum computers

When thinking about today’s quantum computers, I find it useful to draw an analogy with the evolution of digital computers. Just as in the early days of classical computing, quantum machines are characterised by being complex, unwieldy and need to be managed carefully. They use complex mechanical engineering to keep the qubits in their entangled state.

Today’s approaches to quantum computing try to solve optimisation problems that have broad cross-sector applicability, like the fine tuning of supply chains. There are two broadly different approaches, the universal quantum computer and the adiabatic (or annealer) quantum computers such as the machines supplied by D-Wave. Rather than valves and vacuum tubes, today’s first-generation quantum computers use a variety of physical states to create qubits. These include trapped ions, superconductors, semiconductors and nitrogen vacancy diamond to stabilise qubits so they can run calculations and correct errors.

Right now, this demands significant physical infrastructure, often cooling the machine to temperatures near absolute zero and simultaneously keeping the quantum devices in a vacuum. This makes quantum computers look more like the mainframes of old than anything that would sit on a desk or fit in a pocket or bag. However, the innovation and miniaturisation that took the form fit and function of a valve in the 1950s and put over a billion transistors on silicon chips we carry around in our mobile phones is already developing in the quantum computing world.

A question of qubits

Even with such complex construction, today’s first-generation quantum machines suffer from unstable physical qubits with limited capacity and a propensity for errors. So, engineers create logical qubits that use many physical qubits to create stability and correct errors. To be useful for business, there must be at least 49 logical qubits. Complex applications, such as simulations of real-world phenomena, will need closer to 150. The challenge is, every logical qubit potentially needs thousands of physical qubits, but the current record is Google’s 72-qubit Bristlecone processor.

Even so, current quantum computers provide a test environment for experimentation and innovation with quantum algorithms. You certainly won’t want to run your whole organisation off them but testing now will make the transition easier when quantum supremacy, the point at which a quantum computer can perform a task better than a digital computer, arrives.

What can quantum computing do today?

To gain an early advantage, organisations should begin to familiarise themselves with quantum algorithms and source the skills needed to create them. This doesn’t need significant investment in quantum computing infrastructure. IBM, for example, gives access to its quantum devices, processors and simulators via the cloud. Alternatively, organisations could seek to partner with start-ups developing quantum software, as Dow Chemical Company has with 1Qbit. Another option is to create partnerships or sponsorship arrangements with academic institutions researching the technology, as the US Army Research Office did with Yale.

As the first generation of quantum computing evolves over the next decade, a wider range of organisations will have the chance to access quantum-as-a-service capabilities via the cloud and specialised and standardised quantum algorithms. But for first movers, there are opportunities to seize today.

Supercharging financial services

The financial services sector already uses serious computing power to model markets and deliver superior returns in a fiercely competitive environment. Quantum computing could run complex market simulations faster and in parallel, allowing even faster transaction optimisation.

There are opportunities for quantum computing to improve on dynamic portfolio optimisation, pricing options and derivatives, and risk management. There’s also scope to improve algorithms that rely on restrictive assumptions and heuristics imposed by the limitations of conventional machines.

Although in relative infancy today, the market for quantum computing in financial services is likely to grow rapidly as the technology matures. Early experimentation has already begun to explore how quantum computing can optimise arbitrage.

Accelerating drug development and material science

Drug development is a complex business. It needs powerful computers to model how proteins and chemicals interact at the molecular level. And with advances in genetic sequencing and the trend towards personalised treatments, there’s a growing demand to model the effects of new drugs on individuals.

The ability of quantum computers to effectively explore thousands of combinations in parallel, discarding those that don’t work, offers the opportunity to reduce the time, financial and labour costs associated with discovering new treatments.

The benefits of this kind of quantum computing go beyond drug discovery. Such modelling could help computational chemistry and materials science develop new materials, and improve the performance of existing ones, by simulating interactions at the quantum mechanical level.

Finely tuned supply chains and logistics

Quantum computing looks to solve the kind of hard mathematical problems that conventional computers can’t. One classic example is the ‘travelling salesman problem’, where a salesmen needs to visit a number of cities in the minimum amount of time using a variety of transport. Solving this sort of optimisation challenge could significantly improve the design and efficiency of supply chain, logistics and transportation systems worldwide. A 2017 experiment by Volkswagen took less than a second to optimise taxis making the airport run in Beijing, compared to around one hour using a digital computer.

Such optimisations would let organisations respond to everything from the weather to major incidents in real time.

Turbocharging testing and improving resilience

All organisations deal with complexity. Any software system can have millions of lines of code. Hardware can have billions of transistors. The more complex the systems, the more difficult they are to predict. How will they will perform under stress or if you make an update? Take the case of a complex real-time system which must make life or death decisions – the software that flies a plane. Quantum computing has been used in the validation and verification process of old code with a known bug which took a year to find using classical techniques. The quantum computer took a few weeks. When applied to ever more complex new planes, this could reduce the time to market by years, substantially disrupting this market.

Quantum computing’s ability to run complex simulations and parallel calculations can already improve our understanding of how systems react to a range of conditions. This could be a crucial differentiator in contingency planning today.

Will I need an umbrella?

Despite decades of continuously improving computing power, accurately forecasting the weather is still difficult. Quantum computers have the potential to quickly process vast quantities of weather data and conduct analysis that’s too complex for classical computers. The speed of the algorithms can allow the use of real time data to influence the forecasting.

Improved weather forecasting will help all industries, especially transportation, supply chain and logistics, and agriculture. Perhaps quantum computing could even put an end to the British pastime of speculating about the weather.

These are just some of the industries quantum computing is likely to disrupt soon. In the longer term, the world could change beyond recognition.

How will quantum computing evolve?

The opportunities to gain an advantage by experimenting with quantum computers today are promising. But in the coming decades, there will be a quantum revolution. That’s because quantum’s potential far outweighs the threats and barriers to adoption.

Generation one – a time for experimentation and learning

As discussed above, we’re currently at the beginning of the quantum journey with first generation hardware. Today’s quantum computers are analogous to the early days of digital computing, where we needed large, complex machinery for basic calculations.

For this first generation of quantum computing, there are two big hardware challenges. First is the reduction of noise, which causes decoherence in quantum systems leading to loss of quantum properties. Second is improving the stability of physical qubits that perform the underlying error correction for the logical qubits running quantum calculations.

On the software side, the challenge for businesses is in creating the algorithms. Quantum algorithms are fundamentally different from classical computing algorithms and need completely different skillsets. Competition to hire those with quantum programming skills will be fierce.

Generation two – things get cloudy

The second generation of quantum computers are unlikely to arrive within the next decade. But when they do, they will also bring a more mature ‘quantum stack’ that gives organisations access to a more user-friendly and better integrated experience.

Software development kits and APIs will make it easier for all industries to use quantum computing solutions. For many, cloud-based quantum functionality will make more sense than investing in hardware, which is likely to remain mechanically challenging.

The second generation will also see tighter integration with existing technologies to provide hybrid quantum-digital solutions, with the quantum elements optimised to tackle specific classes of modelling and simulation.

Generation three – towards maturity

The third generation of quantum computers, arriving around the mid-2030s, will see the technology continue to build a better-defined stack of ancillary services and cloud accessibility. Quantum software and algorithms will also have matured, making quantum computing applicable to a wider range of problems and attractive to a broad range of industries. Alongside the complex simulation and modelling of earlier generations, there will be new applications in areas like image search and machine learning.

What is still uncertain is whether the third generation will usher in general purpose quantum computers that have the broad range of functions of today’s digital computers. Indeed, the jury is still out on whether a general-purpose quantum machine would even be desirable. Experts speculate that the best results will come from hybrid digital-quantum machines, where the quantum processor handles certain functions in the same way graphics, vector and other specialist processors do today.

It’s also possible that improvements to digital computers could offset some of the benefits of quantum computers, driving them further into specialist applications.

The future of quantum computing is uncertain

As with most aspects of the future, it’s difficult to predict with a high degree of certainty exactly how the quantum computing revolution will unfold. Uncertainty is greatest around when the technology might achieve ‘quantum supremacy’ – the ability of quantum machines to solve problems that classical computers practically can’t. Some believe that it might be achieved as soon as early 2019, while others believe that for practical purposes, it may still be as much as a decade away.

Nonetheless, for some sectors, the potential opportunities presented by quantum computing are significant. Organisations would do well to start investing in understanding the technology now, experimenting with the existing first generation of quantum computers. Those that can’t see how to use the technology today should keep track of its evolution, otherwise they risk missing out on this exciting and transformative technology.