Quantum leap

The quantum computing revolution is coming and could provide huge benefits to sectors right across the economy, writes Amanda Simms

Quantum computers represent a new stage in the evolution of computing. By sidestepping the binary limits of traditional computers, this new breed of technology is set to have huge benefits for sectors such as life sciences, manufacturing and financial services.

Simon Plant, Deputy Director for Innovation at the National Quantum Computing Centre, explains that quantum computers can be extremely fast, solving some problems that would take traditional computers “the entirety of time”.

Siddharth Joshi, a Research Fellow at the Quantum Engineering and Technologies Labs at the University of Bristol, believes the most immediate benefits could be in biochemistry and medicine. “The problem there is if you have these complicated drugs, or compounds, or chemicals, their interactions and how they behave under various circumstances become exceedingly difficult to simulate,” he explains.

Using quantum computers, scientists could potentially accelerate the development of new drugs, saving time and vast amounts of money that could be distributed elsewhere.

Plant says that financial services, manufacturing and logistics will also see early benefits from the technology. He divides the use cases into three categories: simulation, optimisation, and combining with machine learning or artificial intelligence programs.

Qubits

So, what are quantum computers? They work in an entirely new way to the technology that we use today, instead harnessing what happens at the level of individual atoms, electrons or photons, which are governed by the laws of quantum mechanics.

Photos: IBM

A BIT CONFUSED?

Classical BIT Qubit

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Today’s computers translate everything to a zero or a one. These zeros or ones enable us to do the kind of computation we are all used to. But the building blocks of quantum computers, qubits, can be both zero and one at the same time. Qubits can process many inputs simultaneously. This is what makes quantum computers so powerful that they could revolutionise whole sectors.

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Qubit superposition Logic gate In order to manipulate fundamental bits, they must be transformed by logic gates

Measurement A special type of operation at the end of a circuit gives the final values of the qubits

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0or1 Qubits can be both 1 or 0 at the same time

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Result Either 1 or 0 0

“In a normal computer, everything gets translated ultimately to either a zero or a one. And it’s the strings of zeros or ones that allow you to do computation,” explains Joshi. But the building blocks of quantum computers, qubits, can be both zero and one at the same time, a state that is known as superposition. And it is this attribute that allows quantum computers to be so agile.

In fact, when qubits are connected, “what that can do is process many inputs simultaneously. So, you effectively get this parallel processing effect. And that potentially can create a step change in computing power for certain tasks”, notes Plant.

Scaling up

Small-scale, purpose-built quantum computers already exist, their size only reaching tens of qubits at present. IBM has deployed several quantum computers, including a 53-qubit system accessible via cloud – IBM Quantum System One. Meanwhile, some of Google’s quantum technology is offered up to researchers with approved projects, while an open-access scheme called Cirq allows anyone to test quantum algorithms.

However, big tech and academics are working towards realising this technology on a larger scale. “The state which quantum computers are in right now, I would equate this to the very early days of computers,” says Joshi. However, Plant adds that it’s accelerating “very rapidly”. But there are challenges that still need to be overcome.

One is the fact that qubits are immensely fragile and prone to random errors, so must be shielded in protective infrastructure and kept at extremely cold temperatures. Moreover, it’s not just about the hardware, Plant adds, but also about training a next-generation workforce who can progress and make full use of quantum computers.

“Quantum Another challenge that both Joshi and computers work Plant highlight is moving from purpose-built to general-use quantum computers. But in an entirely we should expect to see general-purpose quantum computers in the next decade or so. new way to the Code breaker technology that However, the very thing that makes quantum we use today” computing so powerful also introduces a worrying problem. Think of any piece of encrypted information – from nuclear codes to banking details. This could all be at risk from decryption. Current computers can also do this, just infinitely more slowly, by going through every possible combination. “With the advent of quantum computers, you then have the possibility of running different algorithms that are potentially far, far better at solving this kind of problem. Which means that what you previously thought was secure for 50 years is now secure for five minutes”, explains Joshi. However, this has been recognised as an upcoming issue for a long time – and there are numerous solutions, from changing the type of encryption you use, for example quantum encryption, to a software-based solution known as post-quantum cryptography. All new technology has posed risks or ethical problems of some sort or another, so quantum computing is hardly unique in that regard. More uncertain at this point is overcoming some of the technical challenges to take us from the present day 20-qubit computers to those with 1,000 or even one million qubits. Quantum computers could not only boost the economy and advance scientific progress, but they could also accelerate our ability to solve problems in some of the most pressing issues facing humankind today – from modelling climate change risks and advancing the green energy transition, to averting future pandemics. n