Researchers overcome key challenge to quantum computing

A group of researchers has recently overcome one of the key challenges to quantum computing by simplifying a complex quantum logic operation.

Researchers from Griffith University and the University of Queensland demonstrated this by experimentally realising a challenging circuit the quantum Fredkin gate for the first time.

Dr. Raj Patel said that the allure of quantum computers is the unparalleled processing power that they provide compared to current technology. Much like the everyday computer, the brains of a quantum computer consist of chains of logic gates, although quantum logic gates harness quantum phenomena.

The main stumbling block to actually creating a quantum computer has been in minimising the number of resources needed to efficiently implement processing circuits.

Dr. Patel added that similar to building a huge wall out lots of small bricks, large quantum circuits require very many logic gates to function. However, if larger bricks are used the same wall could be built with far fewer bricks.

Researchers in their experiment demonstrate how one can build larger quantum circuits in a more direct way without using small logic gates.

Usually the Fredkin gate requires implementing a circuit of five logic operations. The research team used the quantum entanglement of photons particles of light to implement the controlled-SWAP operation directly.

Professor Geoff Pryde said what is exciting about their scheme is that it is not limited to just controlling whether qubits are swapped, but can be applied to a variety of different operations opening up ways to control larger circuits efficiently.

The research is published in the journal Science Advances.