Category Physics

Ytterbium: The Quantum Memory of Tomorrow

The photo shows a rare-earth crystal that serves as quantum memory. The crystal is cooled to 3 degrees above absolute zero temperature. Credit: © UNIGE

The photo shows a rare-earth crystal that serves as quantum memory. The crystal is cooled to 3 degrees above absolute zero temperature.
Credit: © UNIGE

Quantum communication and cryptography are the future of high-security communication. But many challenges lie ahead before a worldwide quantum network can be set up, including propagating the quantum signal over long distances. One of the major challenges is to create memories with the capacity to store quantum information carried by light. Researchers at the University of Geneva (UNIGE), Switzerland, in partnership with CNRS, France, have discovered a new material in which an element, ytterbium, can store and protect the fragile quantum information even while operating at high frequencies...

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Nanocrystals Emit Light by Efficiently ‘Tunneling’ Electrons

Illustration of nanosized device made of two joined silver single crystals that generate light by inelastical electron tunneling. Artwork by Steven Bopp

Illustration of nanosized device made of two joined silver single crystals that generate light by inelastical electron tunneling. Artwork by Steven Bopp

Using advanced fabrication techniques, engineers have built a nanosized device out of silver crystals that can generate light by efficiently ‘tunneling’ electrons through a tiny barrier. The work brings plasmonics research a step closer to realizing ultra-compact light sources for high-speed, optical data processing and other on-chip applications.

The device emits light by a quantum mechanical phenomenon known as inelastic electron tunneling. In this process, electrons move through a solid barrier that they cannot classically cross...

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Light-Controlled Polymers can Switch between Sturdy and Soft

MIT chemists have designed a polymer that can reversibly switch from a large structure (orange spheres) to the smaller blue shapes, in response to light. Image: Demin Liu/Molgraphics

MIT chemists have designed a polymer that can reversibly switch from a large structure (orange spheres) to the smaller blue shapes, in response to light.
Image: Demin Liu/Molgraphics

New material reversibly changes its structure in response to different wavelengths of light. MIT researchers have designed a polymer material that can change its structure in response to light, converting from a rigid substance to a softer one that can heal itself when damaged.

“You can switch the material states back and forth, and in each of those states, the material acts as though it were a completely different material, even though it’s made of all the same components,” says Jeremiah Johnson, an associate professor of chemistry at MIT, a member of MIT’s Koch Institute for Integrative Cancer Research and th...

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New Battery could Store Wind and Solar Electricity affordably and at Room Temperature

Sodium-potassium alloy is a room-temperature liquid metal that could unlock a high-voltage flow battery. (Image credit: Antonio Baclig)

Sodium-potassium alloy is a room-temperature liquid metal that could unlock a high-voltage flow battery. (Image credit: Antonio Baclig)

A new type of flow battery that involves a liquid metal more than doubled the maximum voltage of conventional flow batteries and could lead to affordable storage of renewable power. A new combination of materials developed by Stanford researchers may aid in developing a rechargeable battery able to store the large amounts of renewable power created through wind or solar sources. With further development, the new technology could deliver energy to the electric grid quickly, cost effectively and at normal ambient temperatures.

The technology – a type of battery known as a flow battery – has long been considered as a likely candidate for storing intermittent ...

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