Category Technology/Electronics

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...

Depiction of photon recycling inside the crystalline structure of perovskite. Credit: Criss Hohmann

Scientists have discovered that a highly promising group of materials known as hybrid lead halide perovskites can recycle light which could lead to large gains in the efficiency of solar cells. As well as being cheap and easy to produce, perovskite solar cells have, in the space of a few years, become almost as energy-efficient as silicon – the material currently used in most household solar panels.

By showing that they can also be optimised to recycle light, the new study suggests that this could just be the beginning...

Illustration of a graphene nanoribbon with zigzag edges and the precursor molecules used in its manufacture. Electrons on the two zigzag edges display opposite directions of rotation (spin) — “spin-up” on the bottom edge (red) or “spin-down” on the top edge (blue). Credit: EMPA

Scientists have now managed to synthesise GNR with perfectly zigzagged edges using suitable carbon precursor molecules and a perfected manufacturing process. The zigzags followed a very specific geometry along the longitudinal axis of the ribbons. This is an important step, because researchers can thus give graphene ribbons different properties via the geometry of the ribbons and especially via the structure of their edges.

With molecules in a U-shape, which they allowed to grow together to form a snake-like shape, ...

Schematics of structures for three kinds of spin-orbit-torque-induced magnetization scheme. (a) The first previous structure where the magnetization is perpendicular to the film plane. (b) The second previous structure where the magnetization is in-plane and orthogonal to channel current. (c) The new structure where the magnetization is in-plane and collinear with the current. Credit: Shunsuke Fukami

Researchers have developed a new-structure magnetic memory device utilizing spin-orbit- torque-induced magnetization switching. For these 2 decades, much effort has been devoted to the development of magnetic random access memories, which store information as the magnetization direction of a magnet...