Following a number of quantum breakthroughs at Imperial, we sit down with our top quantum experts to explore what quantum could mean for the future.

Imperial College London is a global leader in quantum science and technology, recently testing the first quantum sensor for a future navigation system aboard a Royal Navy ship, recreating the famous double-slit experiment in time, and launching our new Centre for Quantum Engineering, Science and Technology (QuEST) to translate discoveries in quantum science into transformative technologies.

We sit down with Imperial’s top experts in the field to explore what quantum is, what it could mean for the future and what the challenges are to getting there.

We spoke to:

- Dr Joseph Cotter - Advanced Research Fellow in the Department of Physics
- Professor Peter Haynes – Imperial’s Vice-Provost (Education & Student Experience), and Director of QuEST
- Professor Sandrine Heutz - Head of the Department of Materials and co-Director of the London Centre for Nanotechnology
- Professor Myungshik Kim - Chair in Theoretical Quantum Information Sciences in the Quantum Information Theory Group
- Dr Jess Wade - Research Fellow in the Department of Materials
- Professor Ian Walmsley – Imperial’s Provost, and Chair in Experimental Physics

Q – What is quantum physics?

A – Professor Peter Haynes: “Quantum physics is a theory that describes how light and matter behave at the atomic level - saying that they can behave both as particles and waves. This underpins technologies we already heavily rely on, such as semiconductor chips in mobile phones.

“There are two key features of quantum physics - superposition and entanglement.

"If I take a coin, it can be in one of two states - heads or tails. But if I had a quantum coin, its general state would be a combination of heads and tails at the same time. However, when we look at the coin we would find that it is only either heads or tails despite the fact that before we look, it is both. This is called superposition. And it can be exploited in quantum computers, where quantum bits can be both zero and one, rather than just exclusively one or the other.

“For entanglement, if I were to toss two ordinary coins, half of the time, they’ll come out the same – they’ll both be heads, or both be tails. But with quantum coins, I can prepare them in a state such that if one comes out heads, the other will always be tails or vice versa. And this happens even if they are separated by great distances. This strange connection is what we call entanglement. It’s like the two coins are sharing information in a way that goes beyond our everyday understanding of how objects behave. This concept is fundamental to quantum mechanics and is an essential part of understanding how particles behave at the quantum level.”

Q – What features of quantum physics can be useful for technology?

A – Professor Myungshik Kim: “The weird properties of quantum mechanics allow us to understand and manipulate particles at a whole new level. In fact, it’s like Facebook. Last week I purchased a pair of shoes because Facebook knew I was going on holiday and that I needed some new shoes. That’s individual marketing based on individual needs. With quantum mechanics, we can know what individual elementary particles are doing and how they are interacting with each other.

“Work on understanding quantum interactions, which is becoming very important in developing new materials and chemical processes, is getting more difficult to do with even our most powerful supercomputers. We need quantum computers to do it. As an analogy, we can simulate some of the features of human society using monkeys, but there is a limitation. We need humans to simulate humans and quantum computers to simulate or to calculate quantum features of materials.

“Beyond quantum computing, we can exploit other features of the wave-particle nature of matter. One important feature of waves is that they interfere with each other, creating patterns. Those patterns are an important resource for extremely accurate measurement of distances, for example. The much smaller wavelengths of quantum particles make quantum sensors much more accurate than conventional sensors.” 

A - Professor Ian Walmsley: “One area that’s also being explored is the conjunction of AI and quantum mechanics. I think there are two aspects to it. One is, how do we use AI to make quantum machines more easily or improve them? And the second is, does quantum computing or any form of quantum processing allow different kinds of AI? I'd say that the first field is becoming more advanced, and I think people are recognising that is real potential there. The second aspect, I think, is still in its infancy. Nobody really yet understands what a quantum neural network looks like, for example, or what sort of capabilities it will have.”

Q - How is quantum already being used?

A – Professor Ian Walmsley: “There are certain categories of algorithms, which we know will never be solved at scale on any current-generation high-performance computer, but quantum computing makes that possible. It's not a replacement for everything - it's unlikely that we'd have a quantum version of Microsoft Word - but there will be certain things in cryptanalysis and in digital simulations where quantum computers will be able to do things that we cannot currently do, particularly in simulation of new materials for drugs and healthcare, for example. There are also logistics problems like traffic management or the possibility to simulate more complex systems, like financial systems or other social constructs.”

A – Dr Joe Cotter: “Quantum computation has the power to be transformative. At the moment it’s not quite ready, but a number of people here at Imperial and around the world are working on getting to a point where it can be used as a widespread technology.

“There are some other quantum technologies that are a bit more mature. One area is quantum sensing, where we've demonstrated that we can make very, very precise clocks, more sensitive gravimeters to survey underground, and more sensitive magnetometers for brain scans as well as more accurate inertial sensors that you could use for a future satellite-free navigation system. We've deployed these in a number of areas from hospitals to real transportation systems and ships, but what we really need to do now is engineer more robust, more rugged, more usable systems that we can take outside so people in the real world can use these technologies."

Q - What will it take to get these technologies from fundamental research to practical applications?  

A – Professor Sandrine Heutz - “Quantum technologies will require our understanding of the right kinds of platforms and materials at a fundamental level.

“Across campus, this fundamental research is happening alongside efforts to address the engineering challenges. How do we create and characterise optimised materials for quantum technologies? Once we’ve achieved this, then fundamental science, physics and materials can concentrate on each component - for example, making the qubit lifetime longer, or redesigning it so that it can function without the need for cryogenic cooling, which would reduce its energy demands and improve sustainability.

“Then we can begin to understand how the individual quantum components come together to work in a whole quantum system. Understanding and optimising how these components (and their control electronics, interconnects and packaging) come together, how they interface, will make these quantum technologies a reality.”

A – Dr Jess Wade - “These are ultimately technologies that will benefit society, the economy, and national security - so we need the government, the public, the taxpayers, to be on board with whatever we're creating. Luckily Imperial is fantastic at engaging with the public around emerging science and engineering – for example during the annual Great Exhibition Road Festival - and we engage the public early on in the technologies we’re trying to create. How can we harness those relationships, improve public trust and create technologies that society are ready and enthusiastic to use?

“To fully benefit from quantum advantage will require collaborations between highly skilled scientists and innovative end-users. Focusing on public engagement, skills development, and building a diverse quantum community will help realise the technological promise of quantum science.”

Q - How is Imperial driving the future of quantum science and technology research?  

A – Dr Jess Wade: “Imperial’s convening power will be central to our quantum aims. Imperial brings together people with expertise across engineering, physics, materials, chemistry, developing both hardware and software for quantum technologies to succeed. We do a fantastic job of uniting engineers with scientists who are making quantum breakthroughs into a reality - giving people like Joe the integrated electronics that he needs to make his navigation sensors work.

“We can do a lot more to make our community more diverse and more inclusive, welcoming people with different backgrounds and skill sets to push quantum technologies to areas that they haven’t been applied before. One of the government's ambitions is that in the next ten years the UK will have trained 1,000 new PhD students in quantum technologies. At Imperial we’re doing a lot to inspire high school students to consider studying these subjects like physics and materials science at university, and to teach and to develop practical skills in undergraduates. Once trained, it’s important to give these researchers support and opportunities – Imperial is a great place to develop impactful quantum careers. Universities will be critical to delivering the government's technological ambitions.”

A – Professor Peter Haynes: “Our Centre for Quantum Engineering, Science and Technology (QuEST) addresses the need to convene those working on the fundamental science with those with the engineering expertise, translating discoveries in quantum science into transformative quantum technologies. We’ve got three themes: materials for quantum technologies, quantum internet, and the applications of quantum computing.

“There's a certain degree of hype out there about quantum, and Imperial’s expertise in the applications of quantum computing could be useful to help industry dispel some of this. Within Imperial, we've got experts in quantum computing and quantum algorithms who know what the current capabilities of quantum computers are and they're well informed about what their prospects will be. But at the same time, Imperial has a vast community of computational scientists and engineers who are collaborating actively with industrial partners on designing projects and solving problems. So, our classical computing community understands well what the agenda of businesses is, and our quantum community who know what quantum computers can currently do and what they'll be able to do in future. What we’re looking to do is bring these academics and industries together to understand which problems are actually going to be amenable to quantum computing in the future. That way, we can work with companies to help them understand the parts of their business that could be benefitted by quantum computing, and the realistic timescales involved.”

Photography used in this piece has been taken by Thomas Angus.