A cutting-edge start-up founded by a quartet of British university scientists has been valued at $3.2bn (£2.3bn) in one of the largest bets yet on a breakthrough that it is claimed will revolutionise computing.

PsiQuantum, launched by professors at the University of Bristol and Imperial College London, has raised $450m from backers including BlackRock, Microsoft and Scotland’s Baillie Gifford.

The founders, who moved from the UK to Silicon Valley to set up the company in 2016, hope to be the first company to develop a fully-functioning quantum computer in the face of competition from Google and IBM.

The computers use the unusual characteristics of quantum mechanics to create machines that are exponentially more powerful than today’s “classical” designs.

It is expected they will dramatically improve research into medicine, climate patterns and synthetic materials. However, critics warn they pose a potential threat to the encryption protocols that keep data secure.

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PsiQuantum’s co-founders – Jeremy O’Brien, Pete Shadbolt, Mark Thompson and Terry Rudolph – started the company using research developed at Bristol and Imperial, but were urged to move to the US by an investor who said they would find it easier to raise funds.

In total, the company has now raised $665m.

The UK Government has set out plans to become a global leader in quantum computing and promised to invest £153m in projects aiming to commercialise the technology

Mr O’Brien, PsiQuantum’s chief executive, told The Telegraph earlier this year that the company was in talks over setting up a base in Britain, possibly boosting Government plans to prioritise quantum computing.

He said the company was considering setting up a second hub in the UK or continental Europe, which could include a research centre or its own quantum computer.

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Mr O’Brien said: “We’ve maintained links with the UK and in Europe and are in the process of globalising the company. We’re in the process of setting up discussions with UK and EU governments on where we will open up.”

“We believe that there’s a real opportunity here to anchor a global hub around this. There are probably going to be two or three global hubs for quantum computing, and you’d probably put money on the US and China [being two of them].”

Companies such as Google and IBM are investing heavily in quantum computing, while Chinese scientists recently claimed to have followed Google in achieving “quantum supremacy”, building a quantum computer that can outperform a traditional one at a task.

PsiQuantum is seeking to use a different system, based on light signals and existing semiconductor technology, to build the world’s first million-qubit computer, the size it says will be needed to carry out useful calculations.