Nanowerk May 10, 2019 The ability to detect small nano-particles and eventually single molecules remains a challenge. Current attempts focus on microring or microtoroid resonators which enhance the interaction between light and the molecule to be detected. The sensitivity of these devices, however, is limited by their fundamental physics. A team of researchers in the US (Michigan Technological University, University of Central Florida, Pennsylvania State University) propose a type of sensor based on the new notion of exceptional surfaces: surfaces that consist of exceptional points. However, the enhanced sensitivity of exceptional point-based sensors is very sensitive to unavoidable fabrication errors […]
Assessing battery performance: Compared to what?
Eurekalert May 9, 2019 Industrial engineers and researchers from governmental and academic labs often devise their own procedures for characterizing lithium-ion batteries based on the battery technology’s intended application. According to an international team of researchers (UK, USA – University of Hawaii, Argonne National Laboratory) the appropriateness of a test depends on what the investigator is studying. Their comprehensive review analyses and discusses the various international standards and regulations characterisation and electrical testing of lithium-ion cells, specifically for high-power automotive and grid applications. They produced an easy-to-use table comparing eight test methods, including the main equipment needed, the information generated, and […]
Top 10 Science and Technology Inventions for the Week of May 10, 2019
01. Physicists propose perfect material for lasers 02. Flexible, transparent monolayer graphene device for power generation and storage 03. Sculpting super-fast light pulses 04. Researchers take a step towards light-based, brain-like computing chip 05. Air Force Research Laboratory completes successful shoot down of air-launched missiles 06. Machine learning paves the way for next-level quantum sensing 07. Promising material could lead to faster, cheaper computer memory 08. Mimicking squid skin to improve thermoregulating blankets 09. Move over, silicon switches: There’s a new way to compute 10. Novel thermoelectric nanoantenna design for use in solar energy harvesting And others… America may outsmart […]
Sculpting super-fast light pulses
Science Daily May 2, 2019 A team of researchers (NIST, University of Maryland) has demonstrated how dielectric metasurfaces can be leveraged to shape the temporal profile of a near-infrared femtosecond pulse. Finely tailored pulse shaping operations, including splitting, compression, chirping and higher-order distortion are achieved using a Fourier-transform setup embedding metasurfaces able to manipulate, simultaneously and independently, the amplitude and phase of the constituent frequency components of the pulse. Exploiting metasurfaces to manipulate the temporal characteristics of light expands their impact and opens new vistas in the field of ultrafast science and technology…read more. TECHNICAL ARTICLE
Researchers take a step towards light-based, brain-like computing chip
Nanowerk May 8, 2019 Unlike real neural tissue, traditional computing architectures physically separate the core computing functions of memory and processing, making fast, efficient and low-energy computing difficult to achieve. An international team of researchers (Germany, UK) present an all-optical version of a neurosynaptic system, capable of supervised and unsupervised learning. They exploit wavelength division multiplexing techniques to implement a scalable circuit architecture for photonic neural networks, successfully demonstrating pattern recognition directly in the optical domain. Such photonic neurosynaptic networks promise access to the high speed and high bandwidth inherent to optical systems, thus enabling the direct processing of optical […]
Promising material could lead to faster, cheaper computer memory
Science Daily May 2, 2019 Bismuth ferrite (BiFeO3) has the potential to store information much more efficiently than is currently possible. However, its magnetoelectric response is small. Researchers at the University of Arkansas simulated conditions that enhance the magnetoelectric response to the point that it could be used to more efficiently store information by using electricity, rather than magnetism. They found additional oscillations consisting of a mixing between acoustic phonons, optical phonons, and magnons, and reflect the existence of a new quasiparticle that can be coined an “electroacoustic magnon.” The finding could help tune the samples to the magnetostrictive-induced mechanical […]
Physicists propose perfect material for lasers
Eurekalert May 8, 2019 In Weyl semimetals charge carriers behave the way electrons and positrons do in particle accelerators. Researchers in Russia have shown that reactions forbidden for elementary particles can also be forbidden in the crystalline materials known as Weyl semimetals. Specifically, this applies to the forbidden reaction of mutual particle-antiparticle annihilation without light emission. This property suggests that a Weyl semimetal could be the perfect gain medium for lasers. The team gauged the lifetime of an electron-hole pair in a Weyl semimetal to be about 10 nanoseconds which is much longer than in conventional materials used in laser […]
Novel thermoelectric nanoantenna design for use in solar energy harvesting
Nanowerk May 3, 2019 Researchers in Mexico fabricated and compared bimetallic Ni-Pt nanoantennas for a classic and evolutive dipole configuration. Observing the thermoelectric voltage dependence associated with classic and evolutive dipole configuration they found that the evolutive dipole nanoantennas (EDN) generate up to three times more voltage in contrast with the classic dipole nanoantenna (CDN). The evolutive configuration is 1.3 times more efficient than its classical counterpart. The results are corroborated by absorbance of these nanoantennas in the 20 to 36 THz range, where EDN is 40% more efficient than CDN and 30% in the range of 36.1 to 90 […]
A novel method for improving imaging techniques in geophysical and material studies
Science Daily May 7, 2019 Researchers in Japan have developed a method for identifying the location of point-like scatterers based on fluctuations in the physical properties of the surface. They extracted information on the far-field wave properties of the Green’s function by using the so-called “steepest descent path” and “pseudo-projections” methods. Then, the far-field operator was defined based on the near-field observation and the far-field properties of the Green’s function. They used this far-field operator to obtain the indicator functions that determine the position of the scatterers. They successfully demonstrated the reconstruction of densely packed point-like scatterers using the sensor […]
Move over, silicon switches: There’s a new way to compute
Science Daily May 8, 2019 A team of researchers in the US (New York University, University of Iowa) has developed a voltage-controlled topological spin switch (VTOPSS) that uses a hybrid topological insulator–magnetic insulator multiferroic material that can implement Boolean logic operations with sub-10-aJ energy per bit. They have developed the theory of its operation, analytic models of its performance metrics, elucidated performance scaling with dimensions and voltage, and benchmarked it against existing spin-based and CMOS devices. Compared with existing spin-based devices the VTOPSS offers 10–70 times lower energy dissipation and 70–1700 times lower energy-delay product. As it will reduce reliance […]