Usable quantum computer comes closer to reality

Washington, November 16 : Researchers in the United States and at the London Centre for Nanotechnology have moved a step further towards building a usable quantum computer by finding a way to extend the quantum lifetime of electrons by over 5,000 per cent.

Writing about their work in Physical Review Letters, the researchers highlight the fact that electrons exhibit a property called "spin", and work like tiny magnets that can point up, down or a quantum superposition of both.

Given that the state of the spin can be used to store information, according to the researchers, extending their life provides a significant step towards the creation of a usable quantum computer.

"Silicon has dominated the computing industry for decades. The most sensitive way to see the quantum behaviour of electrons held in silicon chips uses electrical currents. Unfortunately, the problem has always been that these currents damage the quantum features under study, degrading their usefulness," says Dr Gavin Morley, lead author of the paper.

Marshall Stoneham, Professor of Physics at UCL (University College London), commented: "Getting the answer from a quantum computation isn't easy. This new work takes us closer to solving the problem by showing how we might read out the state of electron spins in a silicon-based quantum computer."

The team revealed that they achieved the record quantum lifetime by using a magnetic field twenty-five times stronger than those used in previous experiments.

They said that powerful field also provided an additional advantage in the quest for practical quantum computing: it put the electron spins into a convenient starting state by aligning them all in one direction.

ANI