A tiny new world of computing is growing thanks to quantum mechanics. Emma Napper reports
Scientists in Maynooth are trying to build a tiny new computer "brain" that is almost invisible and completely out of this world. Dr Jason Twamley, a senior lecturer at the National University of Ireland in Maynooth, has received €2 million from the EU to develop this new technology, which may one day have massive implications for national security and the way we process information.
Twamley is the leader of the project, which is funded by the EU's Future and Emerging Technologies Programme and involves seven other institutes worldwide. The project aims to build a quantum computer that "thinks" much more efficiently and infinitely faster than a PC. Even the most up-to-date PC can't deal with certain types of problems, such as searching massive databases or tackling a question that could have millions of answers.
For example, if you have a combination lock on your briefcase with three keys it wouldn't take your computer long to search through all the possible combinations. However, if your briefcase has 100,000 keys, a modern PC would take weeks to find out the right number, trying every combination one at a time.
The quantum computer would take only a few seconds to solve this problem. Alarmingly, this new form of computer could also be employed for cracking the codes used to transfer secure information.
Currently, it is almost impossible to crack bank or government security codes, but quantum computers could decode secure information with ease.
The way a quantum computer will work is amazing. All current computers access information in the same way, following instructions stored as a series of "bits". Bits work like a line of spinning tops, that can turn either clockwise or anti-clockwise. If a bit is turning clockwise, the computer reads it as a 1, and if it is turning anti-clockwise it a 0. Letters and numbers are stored as a code using only these two characters.
A quantum computer can look at a series of numbers at the same time and so could find that briefcase combination almost instantly. This is because the bits this computer uses can spin clockwise and anticlockwise at the same time.
That sounds impossible because we are used to a world of big things, where a child's spinning top can turn one way or the other. However, in quantum mechanics each bit is made of a single molecule, which is so small it can break all the normal rules. Scientists realised in the 1930s that small molecules behave differently from bigger objects, but nobody really understands why. "It's weird and fuzzy down there," says Twamley.
He and his team have already managed to make molecules called Buckminsterfullerenes using another €2 million from the EU. "The molecule is a cage of 60 carbon atoms which are arranged in the shape of a soccer ball. Then we throw another atom, such as Nitrogen, inside the cage."
Putting the Nitrogen atom in the cage allows it to behave like a quantum spinning top that can spin clockwise, anti-clockwise or both at once. In a quantum computer it can represent 0 and 1 at the same time.
Taking the idea further, a row of these quantum bits (qubits) could show every number all at the same time, giving an ultra-fast answer to even the most complex problem. A quantum computer with 220 of these qubits "could hold more numbers that there are particles in the universe", says Twamley.
This is Twamley's next challenge, to make the qubits join together to make a powerful computer brain. "The quantum computer won't replace your PC, but it could be used for mainframes in the government and in banks within the next 30 years," he says.
Emma Napper is a research scientist participating in the British Association for the Advancement of Science Media Fellow programme