quantum computers tagged posts

An ORNL-led research team used neutrons (depicted as spheres) to determine the magnetic structure (seen as blue arrows) of an osmium-based material. X-rays (seen as purple waves) revealed the presence of a strong spin orbit effect (illustrated in red). Credit: ORNL/Jill Hemman

An elusive massless particle could exist in a magnetic crystal structure, revealed by neutron and X-ray research. The team studied a material containing the dense element osmium and documented 2 conditions required for the presence of Weyl fermions -predicted in 1929 and observed experimentally in 2015. Researchers are looking for other materials that could host them to harness their unique properties in spintronics and advanced computing applications such as quantum computers.

“Once you have a material that hosts th...

Artistic impression of the sample, the pulse sequence, and the density matrix. Credit: Image by Antti Paraoanu

A superconducting qubit is an artificial atom fabricated on a silicon chip as an electrical circuit made of capacitors and tunnel junctions. This technology is one of the most promising for the realization of quantum computers.

In the experiment, the circuit was operated in a regime where it no longer absorbs or emits electromagnetic waves of certain frequency, as if it would be hiding under an invisibility cloak – hence the term “dark state.” Then, by using a sequence of microwave pulses, the team employed the dark state to realize a transfer of population from the ground energy level to the second energy level, without populating the first energy level...

© Roberto Schirdewahn In order to test cryptographic techniques for microdevices, the researchers develop the central components of the devices and implement them on evaluation platforms.

The Hardware Security Group at the Ruhr-Universität Bochum is currently working towards protecting the data against threats of tomorrow with the devices available today. Due to a novel computation paradigm, quantum computers could break certain cryptographic techniques that are widely used today. We must now brace ourselves for the fact that highly powerful quantum computers may exist in a few years’ time, says Prof Dr.-Ing. Tim Güneysu.

Cryptography is implemented in many devices with a long service life, eg in satellites. Those devices have to remain secure in many years’ to come...