Crash! Scientists explain what happens when nanoparticles collide

Eurekalert  April 4, 2018 To understand the forces that control energy transport at the nanoscale, researchers at SUNY Buffalo focused on small nanoparticles — those with diameters of 5 to 15 nanometers. They found that in collisions, particles of this size behave differently depending on their shape. Nanoparticles with crystal facets transfer energy well, making them an ideal component of materials designed to harvest energy; nanoparticles that are rounder in shape, with amorphous surfaces, adhere to nonlinear force laws making them especially useful for shock mitigation; the behavior of nanoparticles with sharp edges varies depending on sharpness of the edges […]

Finding order in disorder demonstrates a new state of matter

Science Daily  April 2, 2018 In artificial spin ice, which in certain phases appears disordered, the material is ordered, but in a “topological” form. A team of researchers in the US (University of Illinois at Urbana-Champaign, Los Alamos National Laboratory, University of Illinois at Urbana-Champaign, Lawrence Berkeley National Laboratory, University of Minnesota, Yale University) explored a particular artificial spin ice geometry, called Shakti spin ice which could reach its low-energy state as temperature was reduced in successive quenches. Shakti spin ice stubbornly remained at about the same energy level that could be mapped exactly into the “dimer cover model,” whose […]

Exotic state of matter: An atom full of atoms

Science Daily  February 26, 2018 An international team of researchers (USA – Rice University, MIT, Switzerland, Brazil, Austria, Germany) reports spectroscopic observation of Rydberg polarons in an atomic Bose gas. Polarons are created by excitation of Rydberg atoms as impurities in a strontium Bose-Einstein condensate. As computer simulations show, this comparatively weak kind of interaction decreases the total energy of the system, and so a bond between the Rydberg atom and the other atoms inside the electronic orbit is created. This new, weakly bound state of matter is an exciting new possibility of investigating the physics of ultracold atoms… read […]

‘Two-way signaling’ possible with a single quantum particle

Physorg  February 26, 2018 By using a quantum particle that has been put in a superposition of two different locations, researchers in Austria have theoretically shown that both partners are able to encode their messages into a single quantum particle simultaneously. Being in a quantum superposition means that the quantum particle is “simultaneously present” at each partner’s location. Therefore, both partners are able to encode their messages into a single quantum particle simultaneously, a task that is essentially impossible using classical physics. The experimental results show that the communication is secure and anonymous, the direction of communication is hidden—an eavesdropper […]

Major discovery in controlling quantum states of single atoms

Science Daily  February 16, 2018 To protect the quantum properties of a spin, control over its local environment, including energy relaxation and decoherence processes, is crucial. An international team of researchers (South Korea, USA – industry, Germany, Switzerland, Portugal, Spain) was able to precisely image individual iron atoms and measure and control the time that the iron atom can maintain its quantum behavior. They showed that the loss in quantum state superposition is mainly caused by nearby electrons that the researchers injected with extreme control into the iron atom. Understanding these destructive interactions allows us to avoid them in future […]

New hole-punched crystal clears a path for quantum light

Science Daily  February 15, 2018 Researchers at the University of Maryland created a photonic chip that both generates single photons and steers them around. In the new chip, they etched out thousands of triangular holes in an array that resembled a bee’s honeycomb. Along the center of the device they shifted the spacing of the holes, which opens a different kind of travel lane for the light. The team tested the capabilities of the chip by first changing a quantum emitter from its lowest energy state to one of its two higher energy states. When they used photons from the […]

Physicists create new form of light

MIT News  February 15, 2018 A team of researchers in the US (MIT, Harvard University, Princeton University, NITS, University of Chicago) has observed groups of three photons interacting and, in effect, sticking together to form a completely new kind of photonic matter. In controlled experiments, the researchers found that when they shone a very weak laser beam through a dense cloud of ultracold rubidium atoms, rather than exiting the cloud as single, randomly spaced photons, the photons bound together in pairs or triplets, suggesting some kind of interaction — in this case, attraction — taking place among them. According to […]

What causes ionic wind?

Physorg  February 07, 2018 An international team of researchers (South Korea, Slovenia) reports direct evidence that electric wind is caused by an electrohydrodynamic force generated by the charged particle drag as a result of the momentum transfer from electrons/ions to neutral particles. The findings may have applications in reducing the drag force on a vehicle, resulting in the reduction of fuel consumption and reducing flow separation on wind turbine blades… read more. Open Access TECHNICAL ARTICLE