
Erasing data, rather like cleaning a house, should be hard, hot work.
But now a team including Oxford University’s Vlatko Vedral have shown that, in the quantum world at least, it doesn’t always have to be.
They found that, under certain conditions, deleting data held in a quantum computer could actually cool the environment down rather than heating it up. ‘The principle states that in order to erase one bit of information, we need to increase the entropy of the environment by at least as much. In other words we need to dissipate at least one bit of heat into the environment (which is just equal to the bit of entropy times the temperature of the environment).’