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Excuse me, is that solar panel pointing in the right direction?

On a bright morning, graduate student Jeremy Klotz and professor Shree Nayar walked through upper Manhattan with a tall tripod and a camera that takes 360-degree images. Their route took them to bike docking stations, which use solar energy to power their kiosks, docking mechanisms, wireless communication, and even E-bike recharging in recent installations. At each docking station, the researchers raised the camera above the panel, snapped a spherical picture, and sent it to Klotz’s laptop.

Seconds later, the team’s computer vision program told them something remarkable: how much energy that panel would generate in a year—and how much it could generate if it were pointed at the optimal angle.

As it turns out, the solar panels powering the bike docking stations—and likely many solar panels across New York City and other urban destinations—may be leaving significant energy untapped simply because they are not at their best orientation.

Soundwaves settle debate about elusive quantum particle

It was a head-spinning discovery. In 2018, researchers in Japan claimed to find concrete evidence of an elusive particle, a Majorana fermion, in a quantum spin liquid called ruthenium trichloride. Majoranas are highly sought-after by quantum materials scientists because when a pair are localized, or trapped, they can securely encode information and form a stable qubit—the building block of quantum computing.

Some researchers heralded the finding and used it to launch their own studies, while others believed the breakthrough—which was made by measuring what’s called the thermal Hall effect—was actually a mirage caused by defects in the material sample.

Cornell researchers have now waded into the debate and their findings, published in Nature, show both camps were wrong. By measuring the movement of sound waves rather than the flow of heat, the team discovered the thermal Hall effect was caused by rotating lattice vibrations called chiral phonons.

Microfluidic chip reveals how living glioblastoma slices resist chemotherapy

Combining microchip engineering techniques with cutting-edge gene profiling, scientists at Columbia University have developed a new way to study drug responses in living slices of human brain tumor cells. The system, using a type of chip called a microfluidic device, has already revealed new details about how these aggressive tumors resist chemotherapy drugs and could help researchers develop more effective treatments.

The work grew from earlier efforts to study glioblastoma tumors removed from patients during surgery. “These samples that we’re getting from our colleagues who resect these tumors clinically, they’re alive, and we can actually do experiments directly on those surgical samples,” says Peter Sims, Ph.D., associate professor of systems biology at Columbia and senior author on the new study, which appears in the journal Lab on a Chip.

New memory chip survives temperatures hotter than lava

The electronics inside your phone, your car, and every satellite currently orbiting Earth share one critical weakness: heat. Push them past about 200 degrees Celsius and they start to fail. For decades, that thermal ceiling has been one of the hardest walls in engineering. Now a team at the University of Southern California may have just found a way around it.

In a study published in Science, researchers led by Joshua Yang, Arthur B. Freeman Chair Professor at the Ming Hsieh Department of Electrical and Computer Engineering of the USC Viterbi School of Engineering and the USC School of Advanced Computing, report a new type of electronic memory device that kept working reliably at 700 degrees Celsius, hotter than molten lava and far beyond anything previously achieved in its class. The device showed no signs of reaching its limit. Seven hundred degrees was simply as hot as their testing equipment could go.

“You may call it a revolution,” Yang said. “It is the best high-temperature memory ever demonstrated.”

Put a nanodiamond under intense pressure and it becomes flexible

Diamond is among the hardest naturally occurring substances on Earth, but if you shrink it down to the nanoscale, it is surprisingly elastic. And that could be useful for a host of applications such as quantum computing. In a paper published in the journal Physical Review X, Chongxin Shan at Zhengzhou University in China and colleagues studied diamonds as small as four nanometers across to see how they respond to pressure.

Scientists already know that nanodiamonds, which are thousands of times smaller than a grain of sand, can survive being stretched or squeezed in ways that destroy a regular diamond. But nobody knew how.

So the team placed individual nanodiamonds (ranging from 4 to 13 nanometers across) inside a transmission electron microscope between two diamond indenters and compressed them. These were connected to a sensor that measured how strongly each nanodiamond resisted being squeezed while a high-resolution camera imaged diamond atoms as they moved. The researchers backed up their observations with computer simulations.

Laser bursts flip nanoscale magnetic vortices at blistering speeds, opening a path to brain-like spintronics

Spintronics are devices that operate leveraging the spin, an intrinsic form of angular momentum, of electrons. The ability to switch magnetic states is central to the functioning of these devices, as it ultimately allows them to represent binary digits (i.e., “0” and “1”) when processing or storing information.

Some of these devices rely on magnetic vortices, nanoscale whirlpool-like patterns of magnetization that influence the alignment of spins. These vortices possess a property known as helicity, which is essentially the direction in which they rotate.

Reliably switching the helicity of magnetic vortices could open new possibilities for both neuromorphic computing systems, devices that mimic the brain’s neural organization, and multi-state memories. So far, however, this has proved challenging, mainly because it requires a synchronized wave-like rotation of spins without disrupting the geometric structure of vortices.

Pressure-tuned quantum spin liquid-like behavior observed in material Y-kapellasite

A quantum spin liquid is a phase of matter in which the magnetic moments in a material do not align or freeze, even at temperatures close to absolute zero (i.e., at 0 K). The experimental realization of this highly dynamic state could have important implications for the development of quantum computers and other technologies that operate leveraging quantum mechanical effects.

Previous studies have collected evidence that a quantum spin liquid phase emerges in various materials, including herbertsmithite, α-RuCl3, and EtMe3Sb[Pd(dmit)2]2. However, so far none of these materials have been conclusively confirmed to host this state.

Researchers at University Paris-Saclay-CNRS, University of Stuttgart and other institutes in Europe gathered evidence of quantum spin liquid-like behavior in a recently discovered material called Y-kapellasite. Their paper, published in Physical Review Letters, shows that this material is a promising experimental platform for studying exotic states of matter, particularly those driven by quantum magnetism.

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