Quantum Computing won’t supersede classical computing. But it will change everything. And that is an appropriately paradoxical statement, for all things quantum are beyond binary understanding. (Basically, if you find quantum confusing, don’t worry, you’re getting it).

State of play

Despite claims by the tech giants of quantum supremacy (building a machine that outperforms its classical counterpart), right now, there is no clear front-runner and we are still years away from the ‘quantum revolution’. So why are we, as investors, excited by the myriad of startups, many grown in the UK, racing to attain the holy grail: a general-purpose quantum computer?

A fork in the road

Classical computers are good for many things, but when we get down to the very small (the quantum realm), the on/off system of ones and zeroes (bits) that they use is the wrong tool for the job. Even our largest supercomputers can’t cope with the nature of the problems to be solved at these levels. Quantum computers however use qubits that operate on the same quantum principles that defy classical physics. But do not think that a quantum computer is just a more powerful version of the one you’re looking at right now. It is different in a fundamental way. So, it’s best to think of quantum computing as representing a fork in the road, running alongside what we already have, rather than the next iteration. A good analogy here is the Graphics Processing Unit (GPU). A GPU is much better at certain tasks than a Central Processing Unit (CPU) but doesn’t replace it; they work together.

Uses

Using a classical computer to simulate two molecules interacting with each other takes a very long time. It doesn’t matter how fast current computers get, they will never be able to tackle these kinds of tasks as efficiently as quantum computing will. Drug development and chemical research will be revolutionised by quantum computing, because now there will be a computing process that works in the same (weird) way reality does at these quantum levels. Molecular modelling and particle physics will be revolutionised by quantum computers’ ability to perform calculations in this way, but so will other areas such as cryptography, financial modelling, weather forecasting, artificial intelligence and no doubt other sectors we haven’t even considered yet.

The race

The race is on to build a quantum computer that is stable for long enough to deliver on the promise of quantum computing. The ultimate goal is ‘Fault-Tolerant Quantum Computing’, which means a permanently stable quantum computer. There are four approaches that are generally regarded as serious contenders: ion traps; superconducting circuits; silicon matter and silicon photonics. They all have their pros and cons, but there is zero consensus on which has the best chance of winning the race. Even theoreticians, with no vested interests are hedging their bets, so for investors it’s a four horse race. A possible scenario could be that one may show signs of pulling ahead, attract disproportionate investment, and become the self-fulfilling winner. Time will tell, but we believe there will be fault tolerant quantum computers made within the next 10 years.

Hardware first

For now we are in the era of the small, error-prone ‘Noisy Intermediate-Scale Quantum’ (NISQ) and the consensus at present is that there probably isn’t anything quantum computers can do in this era that classical computers can’t. That doesn’t mean there aren’t commercial opportunities. Companies like D-Wave in Canada are making use of quantum ‘weirdness’ to impact the ‘real world’. D-Wave has so far developed more than 200 ‘early quantum’ applications including airline scheduling, election modelling, chemistry simulation, and preventative healthcare; but what they’re doing isn’t what is generally recognised as quantum computing.

There are a lot of teams working on different approaches to quantum computing. As well as the blue-sky R&D departments of Google, IBM and Microsoft, many of the teams focused on achieving it are based in the UK. Centres of excellence include UCL, Bristol, Edinburgh, Oxford and Cambridge but many Universities in the UK have great research going on and the UK has a good co-ordinated programme.

The cutting edge of quantum development remains very thin and it’s a close-knit community. As investors, we’re keen to be as supportive as possible to the individuals and teams who will bring about the next technological revolution.