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Feb 7, 2023

An extension of FermiNet to discover quantum phase transitions

Posted by in categories: chemistry, information science, quantum physics, robotics/AI

Architectures based on artificial neural networks (ANNs) have proved to be very helpful in research settings, as they can quickly analyze vast amounts of data and make accurate predictions. In 2020, Google’s British AI subsidiary DeepMind used a new ANN architecture dubbed the Fermionic neural network (FermiNet) to solve the Schrodinger equation for electrons in molecules, a central problem in the field of chemistry.

The Schroedinger is a partial differential equation based on well-established theory of energy conservation, which can be used to derive information about the behavior of electrons and solve problems related to the properties of matter. Using FermiNet, which is a conceptually simple method, DeepMind could solve this equation in the context of chemistry, attaining very accurate results that were comparable to those obtained using highly sophisticated quantum chemistry techniques.

Researchers at Imperial College London, DeepMind, Lancaster University, and University of Oxford recently adapted the FermiNet architecture to tackle a quantum physics problem. In their paper, published in Physical Review Letters, they specifically used FermiNet to calculate the ground states of periodic Hamiltonians and study the homogenous electron gas (HEG), a simplified quantum mechanical model of electrons interacting in solids.

Feb 7, 2023

Rabi oscillations in a stretching molecule

Posted by in categories: particle physics, quantum physics

Over eighty years ago, Rabi oscillations were proposed to describe the strong coupling and population transfer in a two-level quantum system exposed to an oscillatory driving field. As compared to atoms, molecules have an extra degree of vibration, which adds an additional knob to the Rabi oscillations in light-molecule interactions. However, how such a laser-driven Rabi oscillation during the stretching of molecular bonds determines the kinetic energy release (KER) spectrum of dissociative fragments is still an open question.

In a new article published in Light: Science & Applications, a joint team of scientists, led by Professor Feng He from Shanghai Jiao Tong University and Professor Jian Wu from East China Normal University has investigated Rabi oscillations in a stretching molecule and discovered the strong-field-induced dissociation dynamics beyond the well-accepted resonant one-photon dissociation scenario. During the dissociation of the simplest molecular ion of H2+, coupled with the laser field, the electron hops between the 1sσg and 2pσu states, forming the Rabi oscillations.

The ionization-created nuclear wave packet (NWP) may propagate alternatively along the two potential energy curves towards a larger internuclear distance monotonically, termed as the rolling process, or may propagate outwards along the 2pσu curve followed by the inward propagation in the 1sσg curve and then be relaunched to 2pσu state again followed by subsequent dissociation, termed as the looping process. The rolling and looping dissociation pathways lead to different KERs of the ejected dissociative fragments, which have been verified by comparing experimental measurements with quantum simulation results.

Feb 7, 2023

First-of-its-kind instrument officially ushers in new era of X-ray science

Posted by in categories: bioengineering, biotech/medical, computing, health, science

Arizona State University has officially begun a new chapter in X-ray science with a newly commissioned, first-of-its-kind instrument that will help scientists see deeper into matter and living things. The device, called the compact X-ray light source (CXLS), marked a major milestone in its operations as ASU scientists generated its first X-rays on the night of Feb. 2.

“This marks the beginning of a new era of science with compact accelerator-based X‑ray sources,” said Robert Kaindl, who directs ASU’s Compact X-ray Free Electron Laser (CXFEL) Labs at the Biodesign Institute and is a professor in the Department of Physics. “The CXLS provides hard X-ray pulses with high flux, stability and ultrashort durations, in a very compact footprint. This way, matter can be resolved at its fundamental scales in space and time, enabling new discoveries across many fields — from next-generation materials for computing and information science, to renewable energy, biomolecular dynamics, drug discovery and human health.”

Building the compact X-ray light source is the first phase of a larger CXFEL project, which aims to build two instruments including a coherent X-ray laser. As the first-stage instrument, the ASU CXLS generates a high-flux beam of hard X‑rays, with wavelengths short enough to resolve the atomic structure of complex molecules. Moreover, its output is pulsed at extremely short durations of a few hundred femtoseconds — well below a millionth of one millionth of a second — and thus short enough to directly track the motions of atoms.

Feb 7, 2023

Harvesting big energy from small movement

Posted by in categories: biotech/medical, materials

A new material designed to harvest up to 400 times more energy from movement than currently possible has potential applications in biomedicine and geospatial monitoring.

By Dr Peter Sherrell and Professor Amanda Ellis, University of Melbourne.

Feb 7, 2023

‘Time is not what it used to be’: Children and adults shown to experience time differently

Posted by in category: neuroscience

Researchers at Eötvös Loránd University have investigated whether the perception of time changes with age, and if so, how, and why we perceive the passage of time differently. Their study was published in Scientific Reports.

Time can play tricks on us. Many of us experienced the illusion that those long summers during childhood felt so much longer than the same 3 months feel like now as an adult. While we can argue why one summer may appear longer than the other and how the perception of time can compress and dilate durations depending on various factors, we can easily set up an experiment to gain more insights.

The researchers just did that. They asked how eventfulness affects our duration estimates when probing at different milestones during our cognitive development. They set aside three , 4–5, 9–10, and 18 years and older, and made them watch two videos, 1 minute each. The two videos were extracted from a popular animated series, balanced in visual and acoustic features, except for one feature: eventfulness.

Feb 6, 2023

New cell death mechanism could offer novel cancer treatment strategies

Posted by in category: biotech/medical

A study from researchers at The University of Texas MD Anderson Cancer Center, published today in Nature Cell Biology, details a previously unexplained type of cell death called disulfidptosis that could open the door for novel cancer therapeutic strategies.

As described in the study, disulfidptosis is triggered when cells with high levels of the SLC7A11 protein are subjected to glucose starvation. In preclinical models, treatment with glucose inhibitors induced disulfidptosis in cancer cells with high SLC7A11 expression, effectively suppressing without significant toxicity in normal tissues.

The study was led by Boyi Gan, Ph.D., and Junjie Chen, Ph.D., both professors of Experimental Radiation Oncology.

Feb 6, 2023

Entrepreneur Turns 500 Tonnes of Waste into ‘Black Gold’, Earns Turnover of Crores

Posted by in category: futurism

Watch this video to see how UP resident Sana Khan turned her fascination with earthworms into S J Organics, a vermicomposting venture that sees an annual turnover of Rs 1 crore.

Feb 6, 2023

Scaling and diversifying the talent pipeline will accelerate quantum opportunities

Posted by in categories: business, computing, nanotechnology, quantum physics

The emerging quantum technology industry offers a dynamic career pathway for creative and adaptable physical scientists, as Stuart Woods of Oxford Instruments NanoScience explains.

As quantum technology companies shift gears to translate their applied research endeavours into commercial opportunities – at scale – they’re going to need ready access to a skilled and diverse quantum workforce of “all the talents”. A case study in this regard is Oxford Instruments NanoScience, a division of parent group Oxford Instruments, the long-established UK provider of specialist technologies and services to research and industry.

The NanoScience business unit, for its part, designs and manufactures research tools to support the development, scale-up and commercialization of next-generation quantum technologies. Think cryogenic systems (operating at temperatures as low as 5 mK) and high-performance magnets that enable researchers to harness the exotic properties of quantum mechanics – entanglement, tunnelling, superposition and the like – to yield practical applications in quantum computing, quantum communications, quantum metrology and quantum imaging.

Feb 6, 2023

Which came first: the chicken or the egg?

Posted by in category: futurism

Most biologists will answer confidently when asked ‘which came first, the chicken or the egg? but the answer may depend on what type of egg you’re talking about.

Feb 6, 2023

Scientists pinpoint protein that helps cancer-causing viruses evade immune response

Posted by in category: biotech/medical

The viruses Kaposi sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) have been linked to several cancers. For the first time, UNC School of Medicine scientists have discovered that these viruses use a human protein called barrier-to-autointegration factor 1, or BAF, to evade our innate immune response, allowing the viruses to spread and cause disease.

These findings, published in Nature Communications, suggest that BAF and related proteins could be therapeutic targets to prevent these viruses from spreading and leading to cancers, such as Kaposi sarcoma, non-Hodgkin lymphoma, Hodgkin lymphoma, multicentric Castleman disease, nasopharyngeal carcinoma, and gastric cancer.

“Viruses are in a constant battle with the cellular immune system, which includes the protein cyclic GMP-AMP synthase, or cGAS, which binds to viral DNA and sounds the alarm to trigger immune responses and fight the viral invaders,” said senior author Blossom Damania, Ph.D., the Boshamer Distinguished Professor of Microbiology and Immunology and member of the Lineberger Comprehensive Cancer Center. “We’ve discovered that KSHV and EBV use a different host cell protein, BAF, to prevent cGAS from sounding the alarm.”