Category Physics

Credit: CC0 Public Domain

Typically when scientists make a measurement, they know exactly what kind of measurement they’re making, and their purpose is to obtain a measurement outcome. But in an “unrecorded measurement,” both the type of measurement and the measurement outcome are unknown. Despite the fact that scientists do not know this information, experiments clearly show that unrecorded measurements unavoidably disturb the state of the system being measured for quantum (but not classical) systems. In classical systems, unrecorded measurements have no effect.

Although the information in unrecorded measurements appears to be completely lost, Prof Michael Revzen and Prof Ady Mann have described a protocol that can retrieve some of the lost information...

ORNL’s Michael Manley led a study to discover the key to the success of modern materials used in ultrasound machines and other piezoelectric devices. At the ARCS instrument of the Spallation Neutron Source, he and colleagues studied lattice dynamics in relaxor-based ferroelectrics. Image credit: Oak Ridge National Laboratory, U.S. Dept. of Energy; photographer Genevieve Martin

The lighter wand for your gas BBQ, a submarine’s sonar device and the ultrasound machine at your doctor’s office all rely on piezoelectric materials, which turn mechanical stress into electrical energy, and vice versa. In 1997, researchers developed piezoelectric materials that were 10X better at coupling electrical and mechanical responses than prior state-of-the-art materials...

The thermal metamaterial represented in this graphic could make possible more efficient thermophotovoltaic devices that generate electricity from thermal radiation. Such a technology might be adapted to industrial pipes in factories and power plants, as well as on car engines and automotive exhaust systems, to recapture a portion of the energy wasted as heat. Credit: Purdue University image/Gabriela Sincich and Matthew Bollinger

An international team has used a “thermal metamaterial” to control the emission of radiation at high temperatures, an advance that could bring devices able to efficiently harvest waste heat from power plants and factories. Roughly 50 – 60% of the energy generated in coal and oil-based power plants is wasted as heat...

Regime of a single 1D wire subband filled. Credit: Dr Maria Moreno

Researchers have observed quantum effects in electrons by squeezing them into one-dimensional ‘quantum wires’ and observing the interactions between them. The results could be used to aid in the development of quantum technologies, including quantum computing. Squeezing electrons into a one-dimensional ‘quantum wire’ amplifies their quantum nature to the point that it can be seen, by measuring at what energy and wavelength (or momentum) electrons can be injected into the wire.

“…for electrons in a quantum wire – they repel each other and cannot get past, so if one electron enters or leaves, it excites a compressive wave like the people in the train,” trying to leave a carriage, said Maria Moreno, also from the Cavendish Lab...