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

Quantum simulators wield control over more than 50 qubits, setting new record

Source: Science Daily, November 29, 2017 Two independent teams of researchers in the US (University of Maryland, NIST) and (Harvard University, MIT) have used more than 50 interacting atomic qubits to mimic magnetic quantum matter. UMD-NIST team deployed ytterbium ions trapped in place by gold-coated and razor-sharp electrodes and Harvard-MIT team used rubidium atoms confined by an array of laser beams. In this experiment there are over a quadrillion possible magnet configurations, and this number doubles with each additional magnet. Quantum simulations are believed to be one of the first useful applications of quantum computers. After perfecting these quantum simulators, […]

‘Magnetoelectric’ material shows promise as memory for electronics

Source: Science Daily, November 29, 2017 Devices tend to store information through electric fields or through magnetic fields. In the future, our electronics could benefit from the best of each method. Switching one functionality of a magnetoelectric material induces a change in the other, referred to as cross-coupling. To better understand cross-coupling, an international team if researchers (USA – University of Wisconsin, Temple University, Argonne National Laboratory, Northern Illinois University, Italy, UK, Luxembourg, Switzerland) describe their unique process for making a high-quality magnetoelectric material and exactly how and why it works… read more.  Open Access TECHNICAL ARTICLE

Images of 2017 in physics

Physics World, Dec 15, 2017 We are fortunate at Physics World that the stories we cover are often highly visual. Physics and astronomy are full of eye-catching imagery and we would like to share with you some of our favourite images of 2017… read more.

Fully screen-printed monoPoly silicon solar cell technology

Source: Phys.org, December 14, 2017 The technology developed by researchers in Singapore is applicable on both p-type and n-type silicon wafers, features homogenous junctions and standard fire-thorough screen-printed metal contacts with grids on both sides, resulting in a high-efficiency bifacial solar cell. It uses an advanced tunnel oxide and doped silicon layers, enabling excellent surface passivation in the non-contact cell regions along with very low-resistance and low-recombination screen-printed contacts. Using commercially available large-area Cz-Si wafers they recorded an average cell efficiency of 21.5%… read more.

Teaching life a new trick: Bacteria make boron-carbon bonds

Source: Eurekalert, November 29, 2017 Researchers at Caltech used directed evolution method, where enzymes are evolved in a lab to perform desired functions, to coax the bacteria into making boron-containing compounds. They mutated the DNA that encodes the protein and then put the mutated DNA sequences into thousands of bacterial cells. The DNA of successful mutant proteins was then mutated again, and the cycle was repeated until the bacteria making the proteins were highly proficient at assembling the boron-carbon compounds. Their final bacterial creations were up to 400 times more productive than synthetic chemical processes used for the same reaction. […]

Single-photon detector can count to 4

Source: Nanowerk December 15,2017 A team of researchers in the US (Duke University, Ohio State University, industry) used the superconducting nanowire single-photon detector (SNSPD) method to show multi-photon detection indicating number resolution up to four photons. They paid special attention to the specific shape of the initial spike in the electrical signal to correctly count at least four photons traveling together in a packet. Photon-number-resolution is very useful for a lot of quantum information/communication and quantum optics experiment; it could greatly increase the speed of quantum encryption techniques… read more.  Open Access TECHNICAL ARTICLE

Creating surfaces that repel water and control its flow

Science Daily, December 13, 2017 To gain better control over the flow of water on superhydrophobic materials, scientists have been etching paths into coatings for the liquid to follow. And although water will take the designated path, it can leave behind a wet trail as the rolling droplets have a different contact angle at the front and back. An international team of researchers (China, US – UMass Amherst) has developed a technique to make the tracks hydrophobic which is critical for keeping water droplets’ spherical shape and minimizing the difference in the front and back contact angles. Testing showed that […]