Category Physics

A Quasiparticle that can Transfer Heat under Electrical Control

Because thermal conductivity in this class of materials can be changed with application of an external electric field at room temperature, they hold promise for use in heat switches for everyday applications, like collection of solar power.
Photo: Getty Images

Scientists have found the secret behind a property of solid materials known as ferroelectrics, showing that quasiparticles moving in wave-like patterns among vibrating atoms carry enough heat to turn the material into a thermal switch when an electrical field is applied externally.

A key finding of the study is that this control of thermal conductivity is attributable to the structure of the material rather than any random collisions among atoms...

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Performing Matrix Multiplications at the Speed of Light for Enhanced Cybersecurity

Matrix multiplications at the speed of light
Electro-optic blocks cointegrated for the development of a neuromorphic photonic processor. Credit: Giamougiannis et al., doi 10.1117/1.AP.5.1.016004

“All things are numbers,” avowed Pythagoras. Today, 25 centuries later, algebra and mathematics are everywhere in our lives, whether we see them or not. The Cambrian-like explosion of artificial intelligence (AI) brought numbers even closer to us all, since technological evolution allows for parallel processing of a vast amounts of operations.

Progressively, operations between scalars (numbers) were parallelized into operations between vectors, and subsequently, matrices. Multiplication between matrices now trends as the most time- and energy-demanding operation of contemporary AI computational systems...

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New Type of Solar Cell is being tested in Space

New type of solar cell is being tested in space
Nanowires in three materials imaged by a scanning electron microscope. A thread is a thousand times thinner than a strand of hair. The red and blue colour shows the direction of the current, and that the nanowires work as a tandem solar cell. Credit: Lund University

Physics researchers at Lund University in Sweden recently succeeded in constructing small solar radiation-collecting antennas—nanowires—using three different materials that are a better match for the solar spectrum compared with today’s silicon solar cells. As the nanowires are light and require little material per unit of area, they are now to be installed for tests on satellites, which are powered by solar cells and where efficiency, in combination with low weight, is the most important factor...

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Superconductivity Switches On and Off in ‘Magic-Angle’ Gaphene

A unique device is made of sandwiched layers, with yellow and purple on top and blue on bottom. The middle layer is dark grey representing 2 layers of graphene, and the inset shows the graphene layers creating a moiré pattern. The device has a central rectangular shape with 7 more rectangular shapes emanating from it.
Caption:MIT physicists have found a new way to switch superconductivity on and off in magic-angle graphene. This figure shows a device with two graphene layers in the middle (in dark gray and in inset). The graphene layers are sandwiched in between boron nitride layers (in blue and purple). The angle and alignment of each layer enables the researchers to turn superconductivity on and off in graphene with a short electric pulse.
Credits:Credit: Courtesy of the researchers. Edited by MIT News.

A quick electric pulse completely flips the material’s electronic properties, opening a route to ultrafast, brain-inspired, superconducting electronics...

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