Are Quantum Computers On The Horizon?

The architecture they have devised ought to be relatively easy to scale, and could therefore form the basis of workable quantum computers in the future – with a bit of “engineering effort” and “an enormous amount of money”, according to Isaac Chuang, professor of physics, electrical engineering and computer science at MIT.

Chuang’s team has put together a prototype comprising the first five quantum bits (or qubits) of a quantum computer. This is being tested on mathematical factoring problems, which could have implications for applications that use factoring as the basis for encryption to keep information, including credit card details, secure.

The proof-of-concept has been applied only to the number 15, but the researchers claim that this is the “first scalable implementation” of quantum computing to solve Shor’s algorithm, a quantum algorithm that can quickly calculate the prime factors of large numbers.

“The team was able to keep the quantum system stable by holding the atoms in an ion trap, where they removed an electron from each atom, thereby charging it. They then held each atom in place with an electric field,” explained MIT.

Chuang added: “That way, we know exactly where that atom is in space. Then we do that with another atom, a few microns away – [a distance] about 100th the width of a human hair.

“By having a number of these atoms together, they can still interact with each other because they’re charged. That interaction lets us perform logic gates, which allow us to realise the primitives of the Shor factoring algorithm. The gates we perform can work on any of these kinds of atoms, no matter how large we make the system.”

Chuang is a pioneer in the field of quantum computing. He designed a quantum computer in 2001 based on one molecule that could be held in ‘superposition’ and manipulated with nuclear magnetic resonance to factor the number 15.

The results represented the first experimental realisation of Shor’s algorithm. But the system wasn’t scalable as it became more difficult to control as more atoms were added.

However, the architecture that Chuang and his team have put together is, he believes, highly scalable and will enable the team to build quantum computing devices capable of solving much bigger mathematical factors.

“It might still cost an enormous amount of money to build, [and] you won’t be building a quantum computer and putting it on your desktop anytime soon, but now it’s much more an engineering effort and not a basic physics question,” said Chuang.

In other quantum computing news this week, the UK government has promised £200m to support engineering and physical sciences PhD students and fuel UK research into quantum technologies, although most of the cash will be spent on Doctoral Training Partnerships rather than trying to build workable quantum computing prototypes.

Courtesy-TheInq