Carbon nanotube as ultrafast emitter with narrow energy spread at optical frequency

Nanowerk   January 2, 2018 An international team of researchers (China, Finland) used carbon nanotubes to achieve energy spreads as low as 0.25 eV to demonstrate field-driven ultrafast photo electron emission, in a system capable of much higher phase synchronization than its photon-driven counterpart. According to the researchers, their work will help reshape our understanding of strong field physics, and may very well light the way for entirely new types of electron emission systems. Read more.  TECHNICAL ARTICLE    

Thermoelectric power generation at room temperature: Coming soon?  December 27, 2017 Researchers in Japan combined silicon with ytterbium to create ytterbium silicide which is a good electrical conductor, non-toxic and has valence fluctuation that makes it a good TE material at low temperatures. The Yb atoms in YbSi2 occupy crystal planes and the Si atoms form hexagonal sheets between those planes blocking the conduction of heat through the material keeping the thermal conductivity down. They have achieved high power factor of 2.2 mWm-1K-2 at room temperature. The research could help unlock the benefits of TE in everyday technology. Read more.  TECHNICAL ARTICLE

Innovative transistors based on magnetically induced movement of ions

Nanowerk December 27, 2017 The transport of paramagnetic FeCl4 ions in a liquid electrolyte (including [Bmim]FeCl4) demonstrated by researchers in Japan, was magnetically controlled to operate a typical electrochemical device; an Electric Double Layer Transistor (EDLT), a type of transistor that uses an EDL at a semiconductor/electrolyte interface to tune the electronic carrier density of the semiconductor. The device was successfully switched by a magnetic field, although the switching ratio was smaller than in conventional EDLTs that are controlled by an electric field. The research has the potential to realize innovative applications that have not been possible using conventional approaches. […]

Atomically thin perovskites boost for future electronics  December 27, 2017 High-κ dielectric materials may be the key for developing electronic devices of the future. Researchers in Japan created high-performance dielectric nanofilms using 2-D perovskite nanosheets (Ca2Nam−3NbmO3m+1; m = 3–6) as building blocks. It exhibited an unprecedented capacitance density of approximately 203 μF cm-2, which is about three orders of magnitude greater than that of currently available ceramic condensers, opening a route to ultra-scaled high-density capacitors. The research provides a strategy for achieving 2-D high-κ dielectrics/ferroelectrics for use in ultra-scaled electronics and post-graphene technology. Read more.  TECHNICAL ARTICLE  Credit: National Institute for Materials Science

Deep Learning: A Critical Appraisal

Arxiv January 2, 2018 Although deep learning has historical roots going back decades, neither the term “deep learning” nor the approach was popular just over five years ago. Against a background of considerable progress in areas such as speech recognition, image recognition, and game playing, and considerable enthusiasm in the popular press, the author presents ten concerns for deep learning, and suggests that deep learning must be supplemented by other techniques if we are to reach artificial general intelligence. Read more . Open Access TECHNICAL ARTICLE 

Top 10 Science & Technology Innovations for the Week of December 15, 2017

Ocean of Things Aims to Expand Maritime Awareness across Open Seas A transistor of graphene nanoribbons Researchers make solid ground toward better lithium-ion battery interfaces ‘Magnetoelectric’ material shows promise as memory for electronics Single-photon detector can count to 4 Quantum simulators wield control over more than 50 qubits, setting new record Teaching life a new trick: Bacteria make boron-carbon bonds Fully screen-printed monoPoly silicon solar cell technology Creating surfaces that repel water and control its flow Images of 2017 in physics

Ocean of Things Aims to Expand Maritime Awareness across Open Seas

Source: DARPA, December 6, 2017DARPA’s Ocean of Things program seeks to enable persistent maritime situational awareness over large ocean areas by deploying thousands of small, low-cost floats that could form a distributed sensor network. Each smart float would contain a suite of commercially available sensors to collect environmental data—such as ocean temperature, sea state, and location—as well as activity data about commercial vessels, aircraft, and even maritime mammals moving through the area. The floats would transmit data periodically via satellite to a cloud network for storage and real-time analysis. The technical challenge lies in two key areas: float development and […]

A transistor of graphene nanoribbons

Source: Science Daily, November 29, 2017 Graphene becomes a semiconductor in the form of nanoribbons which has a sufficiently large energy or band gap in which no electron states can exist: it can be turned on and off — and thus may become a key component of nanotransistors. However, graphene ribbons with irregular edges may not exhibit the desired electrical properties. An international team of researchers (USA – UC Berkeley, Switzerland) succeeded in growing ribbons exactly nine atoms wide with a regular armchair edge from precursor molecules. After several process steps, they formed the desired nanoribbons of about one nanometer […]

Researchers make solid ground toward better lithium-ion battery interfaces

Source: Science Daily, December 12, 2017 There are two important interfaces in solid state batteries, at the cathode-electrolyte junction and electrolyte-anode junction. Either could be dictating the performance limits of a full battery. The interfaces that we are only a few atomic layers thick. Researchers at Sandia National Laboratory engineered the interface down to the nanometer or even subnanometer level to study and improve the interfaces between different materials. The underlying goal of the work is to make solid-state batteries more efficient and to improve the interfaces between different materials … read more. TECHNICAL ARTICLE