|Quantum computers could benefit from the latest breakthrough in atomic physics. (Courtesy: Shutterstock)|
A quantum-information analogue of the transistor has been unveiled by two independent groups in Germany and the US. Both devices comprise a single atom that can switch the quantum state of a single photon. The results are a major step towards the development of practical quantum computers.
Unlike conventional computers, which store bits of information in definite values of 0 or 1, quantum computers store information in qubits, which are a superposition of both values. When qubits are entangled, any change in one immediately affects changes in the others. Qubits can therefore work in unison to solve certain complex problems much faster than their classical counterparts.
Qubits can be created from either light or matter, but many researchers believe that the practical quantum computers of the future will have to rely on interactions between both. Unfortunately, light tends only to interact with matter when the light is very intense and the matter is very dense. To make a single photon and a single atom interact is a challenge because the two are much more likely to pass straight through each other.
Physics World: Single-atom gates open the door to quantum computing