Science Alert October 15, 2018 Unlike microwaves, which propagate in wide-angle broadcasts, terahertz waves travel in narrow, very directional beams with a cone angle of less than 2 degrees. A team of researchers in the US (Brown University, Rice University, SUNY Buffalo) set up a direct line-of-site terahertz data link between a transmitter and receiver and experimented with devices capable of intercepting signal. They were able show several strategies that could steal signal without being detected by using a flat piece of metal that could redirect a portion of the beam to a secondary receiver operated by an attacker…read more. […]
Research on light-matter interaction could improve electronic and optoelectronic devices
Eurekalert October 10, 2018 To study low dimensional quantum materials and their quantum effects an international team of researchers (USA – Rensselaer Polytechnic Institute, Florida State University, UC Berkeley, Japan) built a device by stacking multiple atomically thin materials together, including graphene, boron nitride and tungsten diselenide. They showed that as the density of the exciton increases, more electrons and holes pair together, forming four-particle and even five-particle excitonic complexes. They revealed the true biexciton state, a unique four-particle complex responding to light and the nature of the charged biexciton, a five-particle complex. The research gives rise to fundamental understanding […]
Pristine Quantum Light Source Created at the Edge of Silicon Chip
IEEE Spectrum October 10, 2018 Researchers at the University of Maryland injected light into a chip containing an array of miniscule silicon loops arranged in a way that always allows the light to travel undisturbed around the edge of the chip, even if fabrication defects are present. The light circulates around each loop thousands of times before moving on to a neighboring loop. The relatively long journey is necessary to get many pairs single photons out of the silicon chip. Their quantum light source reliably produced high quality, single-color photons time and again, whereas the conventional chip’s output was more […]
Optical gyroscopes the size of a grain of rice and with higher precision
Next Big Future October 10, 2018 Optical gyros have been difficult to scale down because, as they shrink, the signal from their sensors weakens and is then drowned in noise created in part by scattered light. Researchers at Caltech have developed a proof-of-concept device that is capable of detecting phase shifts 30 times smaller than state-of-the-art miniature fibre-optic gyroscopes, despite being 500 times smaller in size. Their approach can enhance the performance of optical gyroscopes by one to two orders of magnitude. Such gyroscopes are great candidates for miniaturization onto nanophotonic platforms…read more. TECHNICAL ARTICLE
New technique locates robots, soldiers in GPS-challenged areas
Science Daily October 9, 2018 Researchers at the US Army Research Laboratory have developed a technique for determining DoA of a radio frequency signal source based on an algorithm that statistically models the received signal strength (RSS) gradient and controls for spatial outliers and correlations. When the signal is extremely noisy, the estimator correctly outputs that no DoA is present and the output is an estimated DoA and associated uncertainty. The technique works in conditions of heavy multipath, does not require any fixed infrastructure, does not rely on prior training data, knowledge about the environment, multiple antennas, or prior calibration […]
New half-light half-matter particles may hold the key to a computing revolution
Nanowerk October 11, 2018 An international team of researchers (UK, France) shows that by embedding the honeycomb metasurface between two reflecting mirrors and changing the distance between them, one can tune the fundamental properties of the Dirac polaritons in a simple, controllable and reversible way. They have shown the ability to slow down or even stop the Dirac particles, and modify their chirality which is impossible to do in graphene itself. The work opens the door for the development of photonic circuitry using these alternative particles and has implications for research in the field of Dirac particles…read more. Open Access […]
MIT has just announced a $1 billion plan to create a new college for AI
MIT Technology Review October 15, 2018 The new college of computing is being built with $350 million in funding from Stephen A. Schwarzman, the CEO and cofounder of a private equity firm. The school will open next September. Under the recent initiative, the Quest for Intelligence, it aims to make breakthroughs in AI by bringing together researchers from cognitive science and neuroscience as well as computer science. According to the president of MIT the new approach was necessary because of the way computing, data, and AI are “reshaping the world”…read more.
Measurement-device-independent quantum communication without encryption
Phys.org October 11, 2018 The key problem of practical quantum secure direct communication (QSDC) is that apparatuses used in practical quantum communication systems have some defects, and these imperfections, especially defects in the measurement devices, can lead to leakage of information and affect the security of practical QSDC. Researchers in China proposed a measurement-and-device-independent quantum secure direct communication protocol using Einstein-Podolsky-Rosen pairs. This protocol eliminates all loopholes related to measurement devices, which solves a key obstacle in practical quantum secure direct communication. The protocol has also an extended communication distance, and a high communication capacity…read more. TECHNICAL ARTICLE
Lift off for world-first ultrasound levitation that bends around barriers
Science Daily October 15, 2018 Researchers in the UK developed SoundBender by overcoming the limitations of previous ultrasound levitation set-ups by developing a hybrid system that combines the versatility of phased arrays of transducers (PATs) with the precision of acoustic metamaterials while helping to eliminate the restrictions on sound field resolution and variability each of the previous approaches applied. The metamaterial provides a low modulator pitch to help create sound fields with high spatial resolution while the PAT adds dynamic amplitude and phase control of the field. They will present their paper at an upcoming ACM conference in Berlin, Germany…read […]
Invention of ionic decision-maker capable of self-learning
Eurekalert October 15, 2018 Researchers in Japan have developed a decision-making ionic device capable of operating using electrochemical phenomena induced by the movement of protons within a solid electrolyte. When the device makes a correct decision, ions migrate toward the electrode associated with the decision. They applied this mechanism to a congested radio communication network and succeeded in demonstrating that the device can select an optimum communication channel to be assigned for a given transmission to achieve the most effective overall channel utilization in relation to changing congestion situations and more complex decisions. The invention may lead to the development […]