Tuesday, June 23, 2020

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A new film made of gold nanoparticles changes color in response to any type of movement. Its unprecedented qualities could allow robots to mimic chameleons and octopi -- among other futuristic applications.
Unlike other materials that try to emulate nature's color changers, this one can respond to any type of movement, like bending or twisting. Robots coated in it could enter spaces that might be dangerous or impossible for humans, and offer information just based on the way they look.
 #materialsscience  #nanomaterials #scienceandtechnology



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Monday, June 22, 2020

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The modern photonics industry is constantly working on making its devices more compact, be it computing systems or sensors and lidars. For this, it is necessary to make lasers, transistors and other elements smaller. A team of scientists led by ITMO researchers proposed a quick and affordable method to create optical chips right in a Petri dish. The research was published in ACS Nano.
#nanotechnology #photonics #Electronics #technology



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Thursday, June 18, 2020

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For the first time, it is now possible to build the stator and the rotor of the electric motor from magnetically finely structured materials and thus make better use of the geometry of the magnetic fields.
#nanotechnology #materialsscience #3dprinting #motors #research #scienceandtechnology




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Tuesday, September 12, 2017

Self-assembling nanoparticle arrays can switch between a mirror and a window



By finely tuning the distance between nanoparticles in a single layer, researchers have made a filter that can change between a mirror and a window.

The development could help scientists create special materials whose optical properties can be changed in real time. These materials could then be used for applications from tuneable optical filters to miniature chemical sensors.

Creating a 'tuneable' material - one which can be accurately controlled - has been a challenge because of the tiny scales involved. In order to tune the optical properties of a single layer of nanoparticles - which are only tens of nanometres in size each - the space between them needs to be set precisely and uniformly.

To form the layer, the team of researchers from Imperial College London created conditions for gold nanoparticles to localise at the interface between two liquids that do not mix. By applying a small voltage across the interface, the team have been able to demonstrate a tuneable nanoparticle layer that can be dense or sparse, allowing for switching between a reflective mirror and a transparent surface. The research is published today in Nature Materials.

Study co-author Professor Joshua Edel, from the Department of Chemistry at Imperial, said: "It's a really fine balance - for a long time we could only get the nanoparticles to clump together when they assembled, rather than being accurately spaced out. But many models and experiments have brought us to the point where we can create a truly tuneable layer."

The distance between the nanoparticles determines whether the layer permits or reflects different wavelengths of light. At one extreme, all the wavelengths are reflected, and the layer acts as a mirror. At the other extreme, where the nanoparticles are dispersed, all wavelengths are permitted through the interface and it acts as a window.

In contrast to previous nanoscopic systems that used chemical means to change the optical properties, the team's electrical system is reversible.



Study co-author Professor Alexei Kornyshev, from the Department of Chemistry at Imperial, said: "Finding the correct conditions to achieve reversibility required fine theory; otherwise it would have been like searching for a needle in a haystack. It was remarkable how closely the theory matched experimental results."

Co-author Professor Anthony Kucernak, also from the Department of Chemistry, commented: "Putting theory into practice can be difficult, as one always has to be aware of material stability limits, so finding the correct electrochemical conditions under which the effect could occur was challenging."

Professor Kornyshev added: "The whole project was only made possible by the unique knowhow and abilities and enthusiasm of the young team members, including Dr Yunuen Montelongo and Dr Debarata Sikdar, amongst others who all have diverse expertise and backgrounds."

Electrotunable nanoplasmonic liquid mirror
Yunuen Montelongo, Debabrata Sikdar, Ye Ma, Alastair J. S. McIntosh, Leonora Velleman, Anthony R. Kucernak,    Joshua B. Edel & Alexei A. Kornyshev
Nature Materials (2017) doi:10.1038/nmat4969


High-speed quantum memory for photons


Physicists from the University of Basel have developed a memory that can store photons. These quantum particles travel at the speed of light and are thus suitable for high-speed data transfer. The researchers were able to store them in an atomic vapor and read them out again later without altering their quantum mechanical properties too much. This memory technology is simple and fast and it could find application in a future quantum Internet. The journal Physical Review Letters has published the results.

Even today, fast data transfer in telecommunication networks employs short light pulses. Ultra broadband technology uses optical fiber links through which information can be transferred at the speed of light. At the receiver's end, the transmitted information has to be stored quickly and without errors so that it can be processed further electronically on computers. To avoid transmission errors, each bit of information is encoded in relatively strong light pulses that each contain at least several hundreds of photons.

For several years, researchers all over the world have been working on operating such networks with single photons. Encoding one bit per photon is not only very efficient, but it also allows for a radically new form of information processing based on the laws of quantum physics. These laws allow a single photon to encode not only the states 0 or 1 of a classic bit, but also to encode a superposition of both states at the same time. Such quantum bits are the basis for quantum information processing that could make unconditionally secure communication and super fast quantum computers possible in the future. The ability to store and retrieve single photons from a quantum memory is a key element for these technologies, which is intensively investigated.

Simple and fast

A team of physicists led by the professors Philipp Treutlein and Richard Warburton from the University of Basel has now developed a particularly simple and fast quantum memory that stores photons in a gas of rubidium atoms. A laser controls the storage and retrieval processes. The technology used does not require cooling devices or complicated vacuum equipment and can be implemented in a highly compact setup. The researchers were also able to verify that the memory has a very low noise level and is suitable for single photons.

One step closer to the quantum internet

"The combination of a simple setup, high bandwidth and low noise level is very promising for future application in quantum networks," says Janik Wolters, first author of the study. The development of such quantum networks is one of the goals of the National Center of Competence in Quantum Science and Technology (NCCR QSIT) and of the EU Framework Programme for Research and Innovation that have funded this study. In the future, quantum networks could lead to unconditionally secure communication, the networking of different quantum computers and the simulation of complex physical, chemical and biological systems.

Simple Atomic Quantum Memory Suitable for Semiconductor Quantum Dot Single Photons
Janik Wolters, Gianni Buser, Andrew Horsley, Lucas Béguin, Andreas Jöckel, Jan-Philipp Jahn, Richard J. Warburton, and Philipp Treutlein
Phys. Rev. Lett. 119, 060502 – Published 8 August 2017