New quantum effect in erasing information in qubits

A bit of information can be encoded in the position of a particle (left or right). A demon can erase a classical bit (blue) by raising one side until the particle is definitely on the right. A quantum particle (red) can also tunnel under the barrier, which generates more heat. Credit: Trinity College Dublin

Researchers from Trinity College Dublin have discovered a uniquely quantum effect in erasing information that may have significant implications for the design of quantum computing chips.

The thermodynamics of computation was brought to the fore in 1961 when Rolf Landauer, then at IBM, discovered a relationship between the dissipation of heat and logically irreversible operations. Landauer discovered that when a bit is erased there is a minimum amount of heat released. This is known as Landauer’s bound and is the definitive link between information theory and thermodynamics.

The scientists at TCD discovered that the quantum nature of the information to be erased can lead to large deviations in the heat dissipation, which is not present in conventional bit erasure.

The paper has been published in Physical Review Letters.

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