Super-fast and ultra-small computers have been brought one step closer to reality with the successful test of a new penny-sized chip.

Close-up of a computer micro chip

Traditional computer micro chips are as small as they are likely to get

The optical quantum chip does away with traditional circuitry and instead uses particles of "whizzing" light.

Scientists asked the "photonic" chip to find the prime factors of 15 and, although it took longer to work it out than a schoolchild could have, it produced the answer - 3 x 5.

The test is a massive breakthrough because it is the first time the chip's processing power has been condensed into such a small size.

Normally to store the same amount of processing power it would need a pack the size of a work bench sitting beside it.

The chip could eventually pave the way for "super-powerful quantum computers".

Cherry Lewis, spokeswoman for the team at Bristol University, explained why we need this technology.

"We are almost getting to the point now where conventional computers cannot go any smaller so we need to go down a completely new route.

"We are talking nano-scale. Particles of light."

Quantum technology aims to exploit the unique properties of quantum mechanics - the physics theory that explains how the world works at microscopic levels.

The main advantage is that unlike transistors in a traditional computer quantum particles can be in two states at the same time.

Also, photons are relatively noise-free and can transmit information at the speed of light.

In the near future the technology could eventually be applied to making internet connections secure, and to developing new materials and medicines.

PhD student Alberto Politi, who performed the experiment with colleague Jonathan Matthews, said: "Finding prime factors may seem like a mathematical abstraction, but the task lies at the heart of modern encryption schemes, including those used for secure internet communication."

The results have been published in the magazine Science.