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Feb 15, 2023

Gate-tunable nanoscale negative refraction of polaritons demonstrated in van der Waals heterostructure

Posted by in categories: computing, nanotechnology

A new study led by DAI Qing’s team from the National Center for Nanoscience and Technology (NCNST) of the Chinese Academy of Sciences (CAS) and Javier Abajo from the Institute of Photonic Sciences (ICFO) in Spain has shown a gate-tunable nanoscale negative refraction of polaritons in the mid-infrared range through a van der Waals heterostructure of graphene and molybdenum trioxide. The atomically thick heterostructures weaken scattering losses at the interface while enabling an actively tunable transition of normal to negative refraction through electrical gating.

The work was published in Science (“Gate-tunable negative refraction of mid-infrared polaritons”).

Basic principle of the “polariton transistor”. The van der Waals heterostructure is constructed by decorating graphene on the molybdenum trioxide, and the antenna stimulates the polariton to transmit through the interface to form negative refraction. (Image: DAI Qing et al.)

Feb 15, 2023

Finely-tuned quantum dots enhance nonlinear optics

Posted by in categories: particle physics, quantum physics

Quantum dots are semiconductor particles measuring just a few nanometres across, which are now widely studied for their intriguing electrical and optical properties.

Through new research published in EPJ B (“Third-order nonlinear susceptibility in CdS/Cdx1Zn 1-x1 S/ZnS multilayer spherical quantum dot,”), Kobra Hasanirokh at Azarbaijan Shahid Madani University in Iran, together with Luay Hashem Abbud at Al-Mustaqbal University College, Iraq, show how quantum dots containing spherical defects can significantly enhance their nonlinear optical properties.

By fine-tuning these defects, researchers could tightly control the frequency and brightness of the light emitted by quantum dots.

Feb 15, 2023

Lego-like universal connector makes assembling stretchable devices a snap

Posted by in categories: robotics/AI, wearables

An international team led by researchers from Nanyang Technological University, Singapore (NTU Singapore) has developed a universal connector to assemble stretchable devices simply and quickly, in a ‘Lego-like’ manner.

Stretchable devices including soft robots and wearable healthcare devices are assembled using several different modules with different material characteristics — some soft, some rigid, and some encapsulated.

However, the commercial pastes (glue), currently used to connect the modules often either fail to transmit mechanical and electrical signals reliably when deformed or break easily.

Feb 15, 2023

Silicon nanoelectronic device hosts ‘flip-flop’ qubit

Posted by in categories: computing, particle physics, quantum physics

A team led by Professor Andrea Morello has just demonstrated the operation of a new type of quantum bit, called ‘flip-flop’ qubit, which combines the exquisite quantum properties of single atoms, with easy controllability using electric signals, just as those used in ordinary computer chips.

“Sometimes new qubits, or new modes of operations, are discovered by lucky accident. But this one was completely by design,” says Prof. Morello. “Our group has had excellent qubits for a decade, but we wanted something that could be controlled electrically, for maximum ease of operation. So we had to invent something completely new.”

Prof. Morello’s group was the first in the world to demonstrate that using the spin of an electron as well as the nuclear spin of a single phosphorus atom in silicon could be used as ‘qubits’ – units of information that are used to make quantum computing calculations. He explains that while both qubits perform exceptionally well on their own, they require oscillating magnetic fields for their operation.

Feb 15, 2023

‘Magic’ solvent creates stronger thin films

Posted by in categories: chemistry, engineering

A new all-dry polymerization technique uses reactive vapors to create thin films with enhanced properties, such as mechanical strength, kinetics and morphology. The synthesis process is gentler on the environment than traditional high-temperature or solution-based manufacturing and could lead to improved polymer coatings for microelectronics, advanced batteries and therapeutics.

“This scalable technique of initiated chemical vapor deposition polymerization allows us to make new materials, without redesigning or revamping the whole chemistry. We just simply add an ‘active’ solvent,” said Rong Yang, assistant professor in the Smith School of Chemical and Biomolecular Engineering in Cornell Engineering. “It’s a little bit like a Lego. You team up with a new connecting piece. There’s a ton you can build now that you couldn’t do before.”

This micrograph image shows an initiated chemical vapor deposition coating made by doctoral student Pengyu Chen in the lab of Rong Yang, assistant professor in the Smith School of Chemical and Biomolecular Engineering in Cornell Engineering. (Image: Cornell University)

Feb 15, 2023

Stopping Alzheimer’s disease before it erases memories, personalities and lives?

Posted by in categories: biotech/medical, neuroscience

Yes, it’s possible. Using genomic technologies and specialized mouse models to develop preventative therapies, JAX scientists aim to stop Alzheimer’s before it starts.

Feb 15, 2023

Largest galaxy in the universe stunning new composite image

Posted by in category: space

A spectacular new photo has been released showing the record-holder for largest galaxy in the universe.

NGC 6872, also known as the Condor Galaxy, stretches 522,000 light years from tip to tip. The Milky Way is approximately 100,000 light years across.

The galaxy is visible in the southern skies as part of the Pavo constellation, and is 212 million light-years from Earth.

Feb 15, 2023

RNA’s ‘joints’ play key role in our gene expression, scientists find

Posted by in categories: biotech/medical, evolution, life extension, neuroscience

University of Chicago scientists have discovered a new wrinkle in our understanding of how our genes work. The team, led by Chuan He, the UChicago John T. Wilson Distinguished Service Professor of Chemistry, Biochemistry and Molecular Biology, shed light on a longstanding puzzle involved in a common way our genes are modified that is known as RNA methylation.

Published Jan. 27 in Science, the finding could have implications for for disease, as well as our picture of gene expression, development, and evolution.

For more than a decade, Chuan He’s laboratory has been focused on trying to unravel the puzzle of a phenomenon called RNA methylation, which we are increasingly understanding plays a key role in our bodies and lives—everything from cancer to PTSD to aging.

Feb 15, 2023

Has the ‘missing’ 70% of the universe FINALLY been found? Scientists find first evidence that black holes are the source of mysterious dark energy

Posted by in category: cosmology

Source of Dark Energy is black holes combined with Einstein’s gravity — experts Result potentially means nothing new has to be added to our picture of Universe It makes up most of the universe, yet hardly anything is known about the so-called Dark Energy that envelopes us. The unusual ‘something’ – one of the great mysteries of cosmology – is believed to be an unknown force that is pushing things apart more strongly than gravity and causing the universe’s expansion to accelerate.

Feb 15, 2023

Generative AI Unlocking Floodgates to Solve Data Scarcity

Posted by in categories: privacy, robotics/AI, transportation

The concept of synthetic data is almost too good to be true – it can mimic the distinctive properties of a dataset while dodging a number of issues that afflict data. There are zero data privacy concerns around synthetic data since it is artificially generated and isn’t related to real-world persons. It can be manufactured on demand and in the volumes required. In other words, synthetic data is a boon in a world eternally thirsty for data.

And the hectic space of generative AI is offering a helping hand in the easy generation of synthetic data.

The concept of synthetic data has been around for decades until the autonomous vehicle (AV) industry started using it commercially in the mid-2010s. But for how important an issue it resolves, creating synthetic data brings a myriad of complications along with it.