Category Technology/Electronics

Carbon tube (center) as a photon source and superconducting nanowires as receivers constitute part of the optical chip. Credit: W.Pernice/WWU

Whether for use in safe data encryption, ultrafast calculation of huge data volumes or so-called quantum simulation of highly complex systems: Optical quantum computers are a source of hope for tomorrow’s computer technology. For the first time, scientists now have succeeded in placing a complete quantum optical structure on a chip. This fulfills one condition for the use of photonic circuits in optical quantum computers.

The light source for the quantum photonic circuit used by the scientists for the first time were special nanotubes made of carbon...

The Scanning Tunnelling Microscope used to inject electrons into a silicon surface at the University of Birmingham. Credit: Michelle Tennison

The findings present a promising step forward towards being able to manipulate and control the behavior of high energy, or ‘hot’, electrons. A Scanning Tunnelling Microscope was used to inject electrons into a silicon surface, decorated with toluene molecules. As the injected charge propagated from the tip, it induced the molecules to react and ‘lift off’ from the surface. By measuring the precise atomic positions from which molecules departed on injection, the team were able to identify that electrons were governed by quantum mechanics close to the tip, and then by more classical behavior further away.

The team found the molecular lift-off was “su...

Generation of one-million-mode continuous-variable cluster state by unlimited time-domain multiplexing,” by Jun-ici Yoshikawa, Shota Yokoyama, Tishiyuki Kaji, Chanond Sornphiphatphong, Yu Shiozawa, Kenzo Makino and Akira Furusawa, APL Photonics, September 27, 2016, scitation.aip.org/content/aip/journal/app/1/6/10.1063/1.4962732.

When the quantum computer was imagined 30 years ago, it was revered for its potential to quickly and accurately complete practical tasks considered impossible for conventional computers. But, there was one big catch: Tiny-scale quantum effects fall apart too easily to be practical for reliably powering computers. Now, a team of scientists in Japan may have overcome this obstacle...

Measurement of the twisting force, or torque, generated by light on a silicon chip holds promise for applications such as miniaturized gyroscopes and sensors to measure magnetic field, which can have significant industrial and consumer impact. Credit: University of Minnesota

Researchers in the University of Minnesota’s College of Science and Engineering have measured the twisting force, or torque, generated by light on a silicon chip. Their work holds promise for applications such as miniaturized gyroscopes and torsional sensors to measure magnetic field, which can have significant industrial and consumer impact. Torque, in the context of light, stems from the spin angular momentum of photons (particles of light), and its measurement is mechanical proof of the quantum nature of light...