Category Physics

The newly synthesized crystal is ferroelectric above room temperature (a-b, e-f) and turns into “plastic phase”, meaning highly deformable, at higher temperature (a to c). The electric polarity of each molecule can be aligned in one direction by applying electric field as it cools (c to e). Credit: Harada J. et al., July 11, 2016, Nature Chemistry, DOI: 10.1038/NCHEM.2567; image is copyrighted

A novel ferroelectric plastic crystal could accelerate the development of more flexible, cost-efficient and less toxic ferroelectrics than those currently in use. Applying an electric field to some materials causes their atoms to “switch” their electric polarization from one direction to another, making one side of the material positive and the other negative...

Using SLAC’s instrument for ultrafast electron diffraction, researchers were able to directly see the motions of atomic nuclei in vibrating molecules for the first time. In the experiment, a laser pulse (green) hit a spray of iodine gas (at right). This stimulated vibrations in the iodine molecules, which consist of two iodine atoms connected via a chemical bond (top left). The molecules were then hit by an electron beam (blue), generating a characteristic diffraction pattern (background) on a detector, from which the separation of the nuclei can be precisely determined. Credit: SLAC National Accelerator Laboratory

Ultrafast electron diffraction (UED) gives new ways to study rapid nuclear motions in nature’s light-dependent processes...

Artistic depiction of the generation of three correlated photons from quantum vacuum. Credit: Antti Paraoanu

Microwaves created at near 0K provide uniquely correlated and controllable states. Researchers at Aalto University have demonstrated the suitability of microwave signals in coding of information for quantum computing. Previous development of the field has been focusing on optical systems. They used a microwave resonator based on extremely sensitive measurement devices, ie superconductive quantum interference devices (SQUIDs). The resonator was cooled down and kept near absolute zero, where thermal motion freezes. This state corresponds to perfect darkness where no photon, a particle of electromagnetic radiation eg visible light or microwaves, is present.

However, in this state (quan...

It is now possible for machines to learn how natural or artificial systems work by observing them, without being told what to look for

It is now possible for machines to learn how natural or artificial systems work by simply observing them, without being told what to look for, according to researchers at the University of Sheffield. This could mean advances in the world of technology with machines able to predict, among other things, human behaviour. The discovery takes inspiration from the work of pioneering computer scientist Alan Turing, who proposed a test, which a machine could pass if it behaved indistinguishably from a human. In this test, an interrogator exchanges messages with two players in a different room: one human, the other a machine.

The interrogator has to find out which o...