Interesting read: Microsoft gambles on a quantum leap in computing

In a laboratory in Copenhagen, scientists believe they are on the verge of a breakthrough that could transform computing.

A team combining Microsoft researchers and Niels Bohr Institute academics is confident that it has found the key to creating a quantum computer.

If they are right, then Microsoft will leap to the front of a race that has a tremendous prize - the power to solve problems that are beyond conventional computers.

In the lab are a series of white cylinders, which are fridges, cooled almost to absolute zero as part of the process of creating a qubit, the building block of a quantum computer.

"This is colder than deep space, it may be the coldest place in the universe," Prof Charlie Marcus tells me.

The team he leads is working in collaboration with other labs in the Netherlands, Australia and the United States in Microsoft's quantum research programme.

Right now, they are behind in the race - the likes of Google, IBM and a Silicon Valley start-up called Rigetti have already shown they can build systems with as many as 50 qubits. Microsoft has yet to demonstrate - in public at least - that it can build one.

But these scientists are going down a different route from their rivals, trying to create qubits using a subatomic particle, whose existence was first suggested back in the 1930s by an Italian physicist Ettore Majorana.

This week scientists from Microsoft's laboratory in Delft published a paper in the journal Nature outlining the progress they had made in isolating the Majorana particle.

Their belief is that this will lead to a much more stable qubit than the methods their rivals are using, which are highly prone to errors. That should mean scaling up to a fully operational quantum computer will be far easier.

At the Copenhagen lab they showed me through a powerful microscope the tiny wire where they have created these Majorana particles. Later over dinner, Prof Charlie Marcus tried, not altogether successfully, to demonstrate to someone whose last physics exam was more than 40 years ago what was unique about this approach with three pieces of bread and some cutlery.

"What's really astounding with this activity compared with what everybody else is doing is that we have to invent a particle that's never existed before and then use it for computing," he explains.

"It's a profoundly more exotic challenge than what's going on with other approaches to quantum computing."

Other scientists taking those other approaches are looking on with great interest and a little scepticism.

"It's one of those things that on paper look incredibly exciting but physics has a habit of throwing up spanners in the works," says University College London's Prof John Morton, whose research involves using good old fashioned silicon to build qubits.

"Until we see the demonstration we don't know how well these Majorana qubits developed by Microsoft will really behave."

He says this is a big year for the field, with the strong likelihood that Google or IBM will demonstrate what is known as quantum supremacy, where a problem that is beyond a conventional supercomputer is solved using quantum methods.

But Microsoft seems confident that its years of research will soon pay off.

"We will have a commercially relevant quantum computer - one that's solving real problems - within five years," says Dr Julie Love, Microsoft's director of quantum computing business development.

She is already out selling the company's customers a vision of a near future where quantum computers will help battle climate change, create new superconducting materials and super-charge machine learning.

"What it allows us to do is solve problems that with all of our supercomputers running in parallel would take the lifetime of the universe to solve in seconds, hours or days."

So, the heat is on for the research team. Prof Charlie Marcus, who spent most of his career at Harvard before being recruited to run the Copenhagen lab, says his life has been about creating knowledge, not building products.

"My job is to find out what works and hand it off to the engineers and computer scientists who will turn it into a technology."

Heading up the whole programme is Todd Holmdahl, the Microsoft executive previously in charge of the Hololens mixed reality headset and the Xbox games console - a measure of how serious the company is about making some quantum hardware pretty soon.

I pressed Prof Marcus on whether his team was going to hit that ambitious five year target set by his employer.

"We're sure going to try," he says with a grin.