While quantum computers containing a small number of qubits are already in existence, they are highly prone to environmental disruption that prevents the technology from being exploited outside of the lab. This includes minor fluctuations in voltage and electromagnetic fields from other electronic equipment, factors that modern computing equipment has been built to withstand.
Furthermore, to make quantum computers usable, scientists need to expand the number of qubits and the size of the machines. This increases the probability that external factors will negatively influence the operation and effectively enforces a limit on the possible number of qubits.
To solve the issue of "environmental noise", the team worked with theoretical scientist Dr Florian Mintert and colleagues from Imperial College London to make use of quantum physics and microwave technology – similar to that used in mobile phones – to help insulate the new computers.
They used radio-frequency and microwave signals capable of manipulating the quantum effects inherent in individual charged atoms (ions) to demonstrate this in practical experiments.
Professor Winfried Hensinger, head of the Ion Quantum Technology Group at the University of Sussex – which last year unveiled the first blueprint for a large-scale quantum computer, said: "With this advance we have made another practical step towards constructing quantum computers that can host millions of qubits.
"Such machines are capable of solving certain problems that even the fastest supercomputer may take billions of years to calculate and be of great benefit to humanity.
"They may be able to help us create new pharmaceuticals, find new cures for diseases such as dementia, create powerful tools for the financial sector, be of benefit to agriculture through more efficient fertiliser production, among many other applications.
"We are only starting to understand the tremendous potential of these machines."
His team is now using the new technique as it puts the final touches to a powerful quantum computer prototype that is currently in its laboratory at the University of Sussex.
He added: "It's now time to translate academic achievements into the construction of practical machines.
"We're in a fantastic position to do this at Sussex and my team is working round the clock to make large-scale quantum computing a future reality."
Intel presented a 49-qubit quantum computer at a keynote in January as it attempts to keep up with IBM's research into the technology.