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May 8, 2020

Finite-temperature violation of the anomalous transverse Wiedemann-Franz law

Posted by in category: particle physics

According to the Wiedemann-Franz (WF) law, the electrical conductivity of a metal is linked to its thermal counterpart, provided that the heat carried by the phonons is negligible and the electrons do not suffer inelastic scattering. In a type II Weyl semimetal also known as a fourth fermion, the thermal dependence of the ratio between electrical and thermal conductivity highlights deviations from the Wiedemann-Franz law. Physicists have tested the WF law in numerous solids but intend to understand the extent of its relevance during anomalous transverse transport and investigate the topological nature of the wave function. In a new report, Liangcai Xu and an international research team in condensed matter physics in China, France, Israel and Germany, presented a study of the anomalous transverse response in a noncollinear antiferromagnetic Weyl semimetal, Mn3Ge. They varied the experimental conditions from room temperature down to sub-Kelvin temperature and observed finite-temperature violation of the WF correlation. They credited the outcome to a mismatch between the thermal and electrical summations of the Berry curvature (a geometric phase acquired within the course of a cycle) and not due to inelastic scattering. The team backed their interpretation with theoretical calculations to reveal a competition between the temperature and Berry curvature distribution. The work is now published on Science Advances.

The Berry curvature of electrons can result in the anomalous Hall effect (AHE) if the host solid lacks time-reversal symmetry (conservation of entropy). While the thermoelectric and thermal counterparts of the anomalous Hall effect are explored less frequently, they too arise from the same fictitious magnetic fields. It remains to be determined how the magnitudes of such anomalous off-diagonal coefficients correlate with each other and if the established correlations between ordinary transport coefficients continue to hold. It is currently laborious to form a semiclassical formula of the anomalous Hall effect (AHE), thereby making any intuitive picture of producing a transverse electric field even more challenging. In this work, the research team presented a study of a magnetic solid, focused on the relation between anomalous electrical and thermal Hall conductivities. Xu et al.

May 8, 2020

Successfully measuring infinitesimal change in mass of individual atoms for the first time

Posted by in categories: chemistry, mobile phones, particle physics, quantum physics

A new door to the quantum world has been opened: When an atom absorbs or releases energy via the quantum leap of an electron, it becomes heavier or lighter. This can be explained by Einstein’s theory of relativity (E = mc2). However, the effect is minuscule for a single atom. Nevertheless, the team of Klaus Blaum and Sergey Eliseev at the Max Planck Institute for Nuclear Physics has successfully measured this infinitesimal change in the mass of individual atoms for the first time. In order to achieve this, they used the ultra-precise Pentatrap atomic balance at the Institute in Heidelberg. The team discovered a previously unobserved quantum state in rhenium, which could be interesting for future atomic clocks. Above all, this extremely sensitive atomic balance enables a better understanding of the complex quantum world of heavy atoms.

Astonishing, but true: If you wind a mechanical watch, it becomes heavier. The same thing happens when you charge your smartphone. This can be explained by the equivalence of energy (E) and mass (m), which Einstein expressed in the most famous formula in physics: E = mc2 (c: speed of light in vacuum). However, this effect is so small that it completely eludes our everyday experience. A conventional balance would not be able to detect it.

But at the Max Planck Institute for Nuclear Physics in Heidelberg, there is a balance that can: Pentatrap. It can measure the minuscule change in mass of a single atom when an electron absorbs or releases energy via a quantum jump, thus opening a for precision physics. Such quantum jumps in the electron shells of atoms shape our world—whether in life-giving photosynthesis and general chemical reactions or in the creation of colour and our vision.

May 8, 2020

Researchers explore quantum computing to discover possible COVID-19 treatments

Posted by in categories: quantum physics, robotics/AI

Quantum machine learning, an emerging field that combines machine learning and quantum physics, is the focus of research to discover possible treatments for COVID-19, according to Penn State researchers led by Swaroop Ghosh, the Joseph R. and Janice M. Monkowski Career Development Assistant Professor of Electrical Engineering and Computer Science and Engineering. The researchers believe that this method could be faster and more economical than the current methods used for drug discovery.

Seed funding from the Penn State Huck Institutes of the Life Sciences, as part of their rapid-response seed funding for research across the University to address COVID-19, is supporting this work.

“Discovering any new drug that can cure a disease is like finding a needle in a haystack,” Ghosh said.

May 8, 2020

In situ Fabrication of Nano ZnO/BCM Biocomposite Based on MA Modified Bacterial Cellulose Membrane for Antibacterial and Wound Healing

Posted by in categories: biotech/medical, chemistry, nanotechnology

Developing an ideal wound dressing that meets the multiple demands of safe and practical, good biocompatibility, superior mechanical property and excellent antibacterial activity is highly desirable for wound healing. Bacterial cellulose (BC) is one of such promising class of biopolymers since it can control wound exudates and can provide moist environment to a wound resulting in better wound healing. However, the lack of antibacterial activity has limited its application.

We prepared a flexible dressing based on a bacterial cellulose membrane and then modified it by chemical crosslinking to prepare in situ synthesis of nZnO/BCM via a facile and eco-friendly approach. Scanning electron microscopy (SEM) results indicated that nZnO/BCM membranes were characterized by an ideal porous structure (pore size: 30~ 90 μm), forming a unique string-beaded morphology. The average water vapor transmission of nZnO/BCM was 2856.60 g/m2/day, which improved the moist environment of nZnO/BCM. ATR-FITR further confirmed the stepwise deposition of nano-zinc oxide. Tensile testing indicated that our nanocomposites were flexible, comfortable and resilient. Bacterial suspension assay and plate counting methods demonstrated that 5wt. % nZnO/BCM possessed excellent antibacterial activity against S.aureus and E. coli, while MTT assay demonstrated that they had no measurable cytotoxicity toward mammalian cells.

May 8, 2020

Scientists demonstrate quantum radar prototype

Posted by in categories: biotech/medical, quantum physics, security

Physicists at the Institute of Science and Technology Austria (IST Austria) have invented a new radar prototype that uses quantum entanglement as a method of object detection. This successful integration of quantum mechanics into devices could significantly impact the biomedical and security industries. The research is published in the journal Science Advances.

Quantum entanglement is a physical phenomenon whereby two particles remain interconnected, sharing physical traits regardless of how far apart they are from one another. Now, scientists from the research group of Professor Johannes Fink at the Institute of Science and Technology Austria (IST Austria) along with collaborators Stefano Pirandola from the Massachusetts Institute of Technology (MIT) and the University of York, UK, and David Vitali from the University of Camerino, Italy—have demonstrated a new type of detection technology called microwave quantum illumination that utilizes entangled as a method of detection. The prototype, which is also known as a quantum , is able to detect objects in noisy thermal environments where classical radar systems often fail. The technology has potential applications for ultra-low power biomedical imaging and security scanners.

May 8, 2020

Hungry monkeys brawl over food as coronavirus hits tourism in Thailand

Posted by in categories: biotech/medical, food

A large crowd of monkeys has been filmed brawling over a pot of yoghurt in a street in Thailand. A fall in tourist numbers amid the Covid-19 outbreak has resulted in far fewer people offering them food. The video was filmed in Lopburi, a city north-east of Bangkok that is famed for its monkey population

How to stop the spread of coronavirus ► https://www.youtube.com/watch?v=3jpXAMwRSu4

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May 8, 2020

CRISPR Used Inside a Person’s Body for the First Time Ever

Posted by in categories: bioengineering, biotech/medical, genetics

Doctors at the Casey Eye Institute at Oregon Health & Science University in Portland have announced the first-ever use of the revolutionary gene editing tool, CRISPR, inside of a person’s body. The tool was used to modify the genes responsible for a particular form of inherited blindness, and those responsible for the pioneering effort say there is real potential here to not only restore the patient’s vision, but open up a new line of medicines specifically used to target and alter DNA.

In an Associated Press report, which comes via NBC, the companies that make the treatment used in the procedure, including Cambridge, Massachusetts-based Editas Medicine and Dublin-based Allergan, highlighted the possibilities moving forward if the trial proves to be successful. Charles Albright, chief scientific officer at Editas, said that “We literally have the potential to take people who are essentially blind and make them see.”

Continue reading “CRISPR Used Inside a Person’s Body for the First Time Ever” »

May 8, 2020

Mushroom sales soar as Americans cook more at home during pandemic

Posted by in category: biotech/medical

EVANSVILLE, Ind., April 17 (UPI) — As produce sales at grocery stores surge during the coronavirus pandemic, one item is selling particularly well — mushrooms.

During the last week of March, fresh mushroom sales were up 18 percent over the same time last year, compared to an 8 percent rise in overall fresh produce sales, according to the Chicago-based data and analytics firm IRI.

“We take heart in those numbers,” said Eric Davis, a spokesman for the Mushroom Council, an industry group based in Redwood Shores, Calif. “We take heart that we’re in that group of staple items. You look for bright spots during this time, and that is one for us.”

May 8, 2020

The animal that regrows its head

Posted by in category: futurism

Could a sea creature with unusual regenerative powers show humans how to do the same? Tracey Logan reports.

May 8, 2020

Direct Laser Cooling to Bose-Einstein Condensation in a Dipole Trap

Posted by in category: futurism

A new scheme for cooling ${}^{87}$Rb to Bose-Einstein condensation uses only lasers, unlike the usual method combining laser and evaporation cooling.