Inside the sub-zero lair of the world's most powerful computer

It looks like a golden chandelier and contains the coldest place in the known universe.

What I am looking at is not just the most powerful computer in the world, but technology pivotal to financial security, Bitcoin, government secrets, the world economy and more.

Quantum computing holds the key to which companies and countries win - and lose - the rest of the 21st Century.

In front of me suspended a metre in the air, in a Google facility in Santa Barbara California, is Willow. Frankly, it was not what I expected.

There are no screens or keyboards, let alone holographic head cams or brain-reading chips.

Willow is an oil barrel-sized series of round discs connected by hundreds of black control wires descending into a bronze liquid helium bath refrigerator keeping the quantum microchip a thousandth of a degree above absolute zero.

It looks, and feels, very eighties, but if quantum's potential is realised, the metal and wire jellyfish structure in front of me will transform the world, in many ways.

"Welcome to our Quantum AI lab," says Hartmut Neven, Google's Quantum AI chief, as we go through the high security door.

Neven is something of a legendary figure, part technological genius, part techno music enthusiast, who dresses like he has snowboarded here straight from the Burning Man music festival – for which he designs art. Perhaps he has, in a parallel universe - more on that later.

His mission is to turn theoretical physics into functional quantum computers "to solve otherwise unsolvable problems" and he admits he's biased but says these chandeliers are the best performing in the world.

Much of our conversation is about what we are not allowed to film in this restricted lab. This critical technology is subject to export controls, secrecy and is at the heart of a race for commercial and economic supremacy. Any small advantage, from the shape of new components to the companies in global supply chains, is a source of potential leverage.

There is a notable Californian vibe in this temple of high science, in its art and colour. Each quantum computer is given a name such as Yakushima or Mendocino, they are each wrapped in a piece of contemporary art, and various graffiti-style murals adorn the walls illuminated by the bright winter sun.

Neven holds up Willow, Google's latest quantum chip, which has delivered two important milestones. He said it settled "once and for all" the discussion about whether quantum computers can do tasks that classical computers can't.

Willow also solved a benchmark problem in minutes that would have taken the best computer in the world 10 septillion years, so more than a trillion trillion, or one with 25 zeros on the end, more than the age of the universe.

This theoretical result was recently applied to the Quantum Echoes algorithm, impossible for conventional computers, which helps learn the structure of molecules from the same technology used in MRI machines.

Neven reels off the ways he believes this Willow quantum chip will be used "to help with many problems that humankind has now".

"It will enable us to discover medicines more efficiently," he says. "It will help us make food production more efficient, it will help us produce energy, to transport energy, to store energy... solve climate change and human hunger."

"It allows us to understand nature much better, and then unlock its secret to build technologies that make life more pleasant for all of us," he tells me.

Some researchers believe that actual Artificial Intelligence will only be truly possible with quantum.

Members of the team here have just received the Nobel prize for the original research into "superconducting qubits" used here.

The Willow chip has 105 qubits. Microsoft's quantum effort has 8 qubits, but uses a different approach. The race around the world is to get to 1 million qubits for a "utility scale machine" that can do quantum chemistry, drug design, without error. The technology is fragile.

What is going on here is being watched carefully around the world. Professor Sir Peter Knight, Chair of the National Quantum Technology Programmes Strategy Advisory Board, says Willow broke new ground.

"All the machines are really still at the toy model stage, they make mistakes. They need error correction. Willow was the first to demonstrate that you could do error correction, through repeated rounds of repairs, which improve," he says.

This puts the technology on a path to being scaled towards accurately doing a trillion operations, perhaps within seven or eight years, rather than the two decades previously assumed.

If the first quarter of this century was defined by the rise of the internet and then Artificial Intelligence, the next 25 years will surely be the start of the quantum era.

Imagine trying to find a tennis ball in one of a thousand closed drawers. A classical computer opens each one in order. A quantum computer opens all of them at the same time. Or similarly, instead of having to need a hundred keys to open a hundred doors in normal computing, quantum enables you to open all one hundred, with one key, instantly.

These machines will not be for everyone. They will not shrink down into phones or AI glasses or laptops. But the point is that the power of these computers grows exponentially, and everyone is getting in on the act.

I asked Nvidia chief Jensen Huang whether this poses a threat to his model of providing the specialised chips for AI. "No, a quantum processor will be added to a computer in the future," he replied.

And one of the UK's leaders in the field points out what is up for grabs in the quantum world - the eventual power to decrypt almost anything from state secrets to Bitcoin.

"All of cryptocurrency will also have to be re-examined because of the quantum computing threat," Sir Peter says.

A top partner to Nvidia last year said that while Bitcoin had a few years yet, the technology needed to fork to a stronger blockchain by the end of the decade.

Tech industry sources refer to the process of "Harvest Now, Decrypt Later" to describe how state agencies are believed to be saving all of the world's encrypted data at home and abroad with the expectation of future generations being able to access it.

And then there is the race across the world. China's approach is very different to the commercial race in the US and the West.

At around $15bn (£11bn), the total resource committed to quantum technology in China is possibly of the order of all the rest of the world's government programmes put together, says Sir Peter.

Since 2022 China has published more scientific papers on quantum than other countries, the efforts have been led by a pioneering physicist called Pan Jianwei. It is a key part of Beijing's 14th five-year plan.

China took a decision to stop its tech companies such as Baidu and Alibaba from developing their own quantum research – and concentrate the people and the infrastructure into a state-run enterprise. China is trying to get the edge on quantum communications and satellites.

Last year, Pan developed and tested the Zuchongzhi 3.0 quantum computer using similar technology though a different approach to that of Willow, claiming similar results. In the autumn it was opened up for commercial use. It all feels a little like the World War Two Manhattan Project to produce the first nuclear weapons, or the Space Race of the 21st Century.

The UK is one of the scientific heartlands for quantum research. It was a British scientist who did the original research on superconducting qubits. There are dozens of companies and cutting-edge research here. The government plans to make a significant investment around this in the coming weeks. It is vital for economics, for military use, and for geopolitics. There is a hope that the UK will be the third power in this area.

Back at the Willow lab, there are perhaps even more existential questions being posed. Last year Neven suggested that Willow's unprecedented speed supported some conceptions of the existence of a multiverse. Basically this speed could be explained by Willow having tapped into parallel universes for its compute power. Not all scientists bought this.

"There is still a spirited debate," he tells me. "As you have learned in your lab visit, the reason quantum computers are so powerful is that within one clock cycle it can touch two to the 105 combinations simultaneously. It makes you question where are these different things?… There's a version of quantum mechanics to think about - the many worlds formulation - parallel universes or parallel reality."

Willow had not proved this, Neven was careful to say, but was "suggestive that we should take this idea seriously".

This is the cutting edge of the frontier of the world, of technology, of growth, and the British government will soon pour hundreds of millions into catching up with Willow and the Chinese. It sounds like science fiction. It is rapidly becoming economic fact.