Science Daily June 11, 2020 Device-independent quantum key distribution provides security even when the equipment used to communicate over the quantum channel is largely uncharacterized. A central obstacle in photonic implementations is that the global detection efficiency, i.e., the probability that the signals sent over the quantum channel are successfully received, must be above a certain threshold. Researchers in Switzerland developed a protocol that adds artificial noise, which cannot be known or controlled by an adversary, to the initial measurement data (the raw key). Focusing on a realistic photonic setup using a source based on spontaneous parametric down conversion, they […]
Author Archives: Hema Viswanath
A breakthrough in developing multi-watt terahertz lasers
Phys.org June 11, 2020 Plasmonic lasers suffer from low output power and divergent beams due to their subwavelength metallic cavities. A team of researchers in the US (Leigh University, Sandia National Laboratory) longitudinally coupled an array of metallic microcavities through traveling plasmon waves which led to radiation in a single spectral mode and a diffraction limited single-lobed beam in the surface normal direction. They implemented the scheme for terahertz plasmonic quantum-cascade lasers and measured peak output power in excess of 2W for a single-mode 3.3THz QCL radiating in a narrow single-lobed beam, when operated at 58K in a compact Stirling […]
Combining magnetic data storage and logic
Phys.org June 16, 2020 Researchers in Switzerland built racetrack memory managed to perform logical operations directly within memory element. The racetrack memory elements work by using current pulses to move tiny magnetic domains up and down nanowires that are just a few hundred nanometres thick. In these domains, all the magnetic moments are oriented in the same direction and can thus be used to represent the binary states 0 and 1. They use an electric current to reverse the polarity of the magnetic regions, thereby performing a NOT operation on the stored data. By eliminating the need for the mechanical […]
Laser technology: The turbulence and the comb
Nanowerk June 18, 2020 While investigating circular quantum cascade lasers, an international team of researchers (USA – Harvard University, Texas A&M, Yale University, Italy, Austria) found out that the circular mini-lasers can be used in a very simple way to produce frequency combs. They found that turbulence is the driving force that causes the oscillation leading to frequency combs. Optical frequency comb can be used to build tiny chemical sensors…read more. TECHNICAL ARTICLE
Engineers develop new fuel cells with twice the operating voltage as hydrogen
EurekAlert June 17, 2020 Researchers at Washington University have developed high-power direct borohydride fuel cells that operate at double the voltage of conventional hydrogen fuel cells. They pioneered a reactant identifying an optimal range of flow rates, flow field architectures and residence times that enable high power operation ensuring proper fuel and oxidant distribution and the mitigation of parasitic reactions. They demonstrated a single-cell operating voltage of 1.4 or greater, double that obtained in conventional hydrogen fuel cells, with peak powers approaching 1 watt/cm2. Doubling the voltage would allow for a smaller, lighter, more efficient fuel cell design. Their approach […]
Life sciences open their doors for engineers
EurekAlert June 15, 2020 Research infrastructures are increasingly important to research and development activity by providing access to the latest detection, imaging, computational and research techniques at scale. To address this problem, EMBL developed Accelerator for Research Infrastructure Scientists (ARISE) Programme, funded by EU, for future research infrastructure scientists. During their three-year fellowship experienced STEM (science, technology, engineering, mathematics) professionals will develop into future leaders in technology development and the operation of advanced life science research infrastructures in Europe. They will work on a wide range of research and technology development in the different areas including imaging, bioinformatics, data science […]
Microbe-killing short-wavelength UV radiation produced by LEDs
Physics World June 16, 2020 Researchers in Germany have developed a prototype device that incorporates emerging LED technology. It features an array of 118 LEDs spread over an area of 64 cm2 and emitting UV light at a wavelength of around 230 nm. The setup delivered a maximum irradiation power of 0.2 mW/cm2 over an area of 36 cm2, with 90% uniformity. They assess the performance of their device using tissue samples of both skin and mucous membrane to determine the extent of damage to DNA caused by varying doses of light and compare the pathogen-killing effectiveness of the radiation […]
Molecular robot swarms
Nanowerk June 18, 2020 Swarming of molecular robots has emerged as a new paradigm with potentials to overcome the hurdles in molecular robotics. In this article researchers in Japan review the recent progress and future challenges in molecular robotics. They discuss the latest developments in swarm molecular robotics, particularly emphasizing the effective utilization of bio- and nanotechnology in swarming of molecular robots. Importance of tuning the mutual interaction among the molecular robots in regulation of their swarming is introduced. Successful utilization of DNA, photoresponsive molecules, and natural molecular machines in swarming of molecular robots to provide them with processing, sensing, […]
A new platform to stretch 2D materials
Nanowerk June 17, 2020 As the electronic and optical properties of 2D materials can be controlled by mechanical deformations of their crystal structure, strain engineering can be used to modify their electronic properties. Researchers in Spain have developed thermal strain actuators on top of polypropylene substrates to control the biaxial strain in atomically thin MoS2 layers. The actuators can reach a maximum biaxial strain of 0.64 % and reliably modulated at frequencies up to 8 Hz. The strain levels can be varied all the way from 0% to 0.6% with a negligible spatial drift. They demonstrated the operation of the […]
New techniques improve quantum communication, entangle phonons
Phys.org June 17, 2020 A team of researchers in the US (University of Chicago, Argonne National Laboratory, UC Santa Barbara) developed a system that entangled two communication nodes using microwave photons through a microwave cable about a meter in length. By turning the system on and off in a controlled manner, they were able to quantum-entangle the two nodes and send information between them without ever having to send photons through the cable. In principle, this would also work over a much longer distance. Using a system built to communicate with phonons, they entangled two microwave phonons. They used one […]