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Scientists discover a topological magnet that exhibits exotic quantum effects

An international team led by researchers at Princeton University has uncovered a new class of magnet that exhibits novel quantum effects that extend to room temperature.

The researchers discovered a quantized topological phase in a pristine magnet. Their findings provide insights into a 30-year-old theory of how electrons spontaneously quantize and demonstrate a proof-of-principle method to discover new topological magnets. Quantum magnets are promising platforms for dissipationless current, high storage capacity and future green technologies. The study was published in the journal Nature this week.

The discovery’s roots lie in the workings of the quantum Hall effect- a form of topological effect which was the subject of the Nobel Prize in Physics in 1985. This was the first time that a branch of theoretical mathematics, called topology, would start to fundamentally change how we describe and classify matter that makes up the world around us. Ever since, topological phases have been intensely studied in science and engineering. Many new classes of quantum materials with topological electronic structures have been found, including topological insulators and Weyl semimetals. However, while some of the most exciting theoretical ideas require , most materials explored have been nonmagnetic and show no quantization, leaving many tantalizing possibilities unfulfilled.

CRISPR C-to-G base editors for inducing targeted DNA transversions in human cells

CRISPR-guided DNA cytosine and adenine base editors are widely used for many applications1,2,3,4 but primarily create DNA base transitions (that is, pyrimidine-to-pyrimidine or purine-to-purine). Here we describe the engineering of two base editor architectures that can efficiently induce targeted C-to-G base transversions, with reduced levels of unwanted C-to-W (W = A or T) and indel mutations. One of these C-to-G base editors (CGBE1), consists of an RNA-guided Cas9 nickase, an Escherichia coli –derived uracil DNA N-glycosylase (eUNG) and a rat APOBEC1 cytidine deaminase variant (R33A) previously shown to have reduced off-target RNA and DNA editing activities5,6. We show that CGBE1 can efficiently induce C-to-G edits, particularly in AT-rich sequence contexts in human cells. We also removed the eUNG domain to yield miniCGBE1, which reduced indel frequencies but only modestly decreased editing efficiency. CGBE1 and miniCGBE1 enable C-to-G edits and will serve as a basis for optimizing C-to-G base editors for research and therapeutic applications.

Improved Advanced Energy Storage Using New Nano-Engineering Strategy

New types of cathodes, suitable for advanced energy storage, can be developed using beyond-lithium ion batteries.

The rapid development of renewable energy resources has triggered tremendous demands in large-scale, cost-efficient and high-energy-density stationary energy storage systems.

Lithium ion batteries (LIBs) have many advantages but there are much more abundant metallic elements available such as sodium, potassium, zinc and aluminum.

Scientists achieve major breakthrough in preserving integrity of sound waves

In a breakthrough for physics and engineering, researchers from the Photonics Initiative at the Advanced Science Research Center at The Graduate Center, CUNY (CUNY ASRC) and from Georgia Tech have presented the first demonstration of topological order based on time modulations. This advancement allows the researchers to propagate sound waves along the boundaries of topological metamaterials without the risk of waves traveling backwards or being thwarted by material defects.

The new findings, which appear in the journal Science Advances, will pave the way for cheaper, lighter devices that use less battery power, and which can function in harsh or hazardous environments. Andrea Alù, founding director of the CUNY ASRC Photonics Initiative and Professor of Physics at The Graduate Center, CUNY, and postdoctoral research associate Xiang Ni were authors on the paper, together with Amir Ardabi and Michael Leamy from Georgia Tech.

The field of topology examines properties of an object that are not affected by continuous deformations. In a topological insulator, electrical currents can flow along the object’s boundaries, and this flow is resistant to being interrupted by the object’s imperfections. Recent progress in the field of metamaterials has extended these features to control the propagation of sound and light following similar principles.

More Details On NASA’s VERITAS Mission, Which Could Go to Venus

Venus has always been a bit of the odd stepchild in the solar system. It’s similarities to Earth are uncanny: roughly the same size, mass, and distance from the sun. But the development paths the two planets ended up taking were very different, with one being the birthplace of all life as we know it, and the other becoming a cloud-covered, highly pressurized version of hell. That cloud cover, which is partially made up of sulfuric acid, has also given the planet an air of mystery. So much so that astronomers in the early 20th century speculated that there could be dinosaurs roaming about on the surface.

Some of that mystery will melt away if a team from NASA’s Jet Propulsion Laboratory gets a chance to launch their newest idea for a mission to the planet, the Venus Emissivity, Radio Science, InSAR, Topograph, and Spectroscopy (or VERITAS) mission.

VERITAS, which means “truth” in Latin, will seek to understand several truths about Venus. To do this it will rely, like all NASA missions on the instruments that make up its scientific payload. Since VERITAS is planned as an orbiter rather than a lander, its instrumentation will focus primarily on remote sensing. It will house two primary instruments, the Venus Emissivity Mapper (VEM) and the Venus Interferometric Synthetic Aperture Radar (VISAR). VERITAS will also be able to do some additional science without even needing a stand-alone instrument. In a neat bit of engineering innovation, the telecommunication system that the satellite uses to send data back to Earth will also be used to map the strength of variations in Venus’ gravitational field.

Neuroscientists at Vanderbilt identify the brain cells that help humans adapt to change

A team of researchers with interdisciplinary expertise in psychology, informatics (the application of information science to solve problems with data) and engineering along with the Vanderbilt Brain Institute (VBI) gained critical insights into one of the biggest mysteries in neuroscience, identifying the location and critical nature of these neurons.”


New research on cognitive flexibility points to a small class of brain cells that support switching attention strategies when old strategies fail.

Neuroscientists identify the brain cells that help humans adapt to change

There are 86 billion neurons, or cells, in the human brain. Of these, an infinitely small portion of them handle cognitive flexibility—our ability to adjust to new environments and concepts.

A team of researchers with interdisciplinary expertise in psychology, informatics (the application of information science to solve problems with data) and engineering along with the Vanderbilt Brain Institute (VBI) gained critical insights into one of the biggest mysteries in neuroscience, identifying the location and critical nature of these neurons.

The article was published in the journal Proceedings of the National Academy of Science (PNAS) on July 13. The discovery presents an opportunity to enhance researchers’ understanding and treatment of mental illnesses rooted in cognitive flexibility.

Tiny bubbles make a quantum leap

July 13, 2020—Researchers at Columbia Engineering and Montana State University report today that they have found that placing sufficient strain in a 2-D material—tungsten diselenide (WSe2)—creates localized states that can yield single-photon emitters. Using sophisticated optical microscopy techniques developed at Columbia over the past three years, the team was able to directly image these states for the first time, revealing that even at room temperature they are highly tunable and act as quantum dots, tightly confined pieces of semiconductors that emit light.

“Our discovery is very exciting, because it means we can now position a emitter wherever we want, and tune its properties, such as the color of the emitted photon, simply by bending or straining the material at a specific location,” says James Schuck, associate professor of mechanical engineering, who co-led the study published today by Nature Nanotechnology. “Knowing just where and how to tune the single-photon is essential to creating quantum optical circuitry for use in quantum computers, or even in so-called ‘quantum’ simulators that mimic physical phenomena far too complex to model with today’s computers.”

Developing such as quantum computers and quantum sensors is a rapidly developing field of research as researchers figure out how to use the unique properties of quantum physics to create devices that can be much more efficient, faster, and more sensitive than existing technologies. For instance, quantum information—think encrypted messages—would be much more secure.

Liquid crystals create easy-to-read, color-changing sensors

Chameleons are famous for their color-changing abilities. Depending on their body temperature or mood, their nervous system directs skin tissue that contains nanocrystals to expand or contract, changing how the nanocrystals reflect light and turning the reptile’s skin a rainbow of colors.

Inspired by this, scientists at the Pritzker School of Molecular Engineering (PME) at the University of Chicago have developed a way to stretch and strain liquid crystals to generate different colors.

By creating a thin film of polymer filled with liquid crystal droplets and then manipulating it, they have determined the fundamentals for a color-changing sensing system that could be used for smart coatings, sensors, and even wearable electronics.