Quantum computing tagged posts

An artist’s rendering of the quantum Fredkin (controlled-SWAP) gate, powered by entanglement, operating on photonic qubits. Credit: Raj Patel and Geoff Pryde, Center for Quantum Dynamics, Griffith University.

The quantum circuit Fredkin gate has been experimentally realised for the first time. “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,” said Dr Patel. “We demonstrate in our experiment how one can build larger quantum circuits in a more direct way without using small logic gates.”

At present, even small and medium scale quantum computer circuits cannot be produced because of the requirement to integrate so many of these gate...

Photons are generated simultaneously in pairs, each in one of the photon streams. The detection of photons in one stream indicates the timing information of those in the other. Using this information, a proper timing control is dynamically applied to those photons so they appear at regular intervals. This new technique increases the rate of photons at the regular interval, which is extremely useful for quantum secure communication and quantum photonic computation. Credit: University of Sydney

The interdisciplinary research is set to revolutionize our ability to exchange data securely – along with advancing quantum computing, which can search large databases exponentially faster...

This image shows inside the laboratories at ANFF, where the researchers designed and built the world’s first two-qubit logic gate. Credit: UNSW

Quantum logic gate in silicon built for the for the first time, making calculations between 2 qubits of information possible – and thereby clearing the final hurdle to making silicon quantum computers a reality. “What we have is a game changer,” said Andrew Dzurak, Scientia Professor and Director of the Australian National Fabrication Facility at UNSW. “Because we use essentially the same device technology as existing computer chips, we believe it will be much easier to manufacture a full-scale processor chip than for any of the leading designs, which rely on more exotic technologies.”

In classical computers, data is rendered as binary bits, which ...