Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics – Page 308

“Scientists suspect that a ”fifth force” may be at work in space. This force, which they believe is mediated by a hypothetical particle called a symmetron is responsible for creating invisible walls in space.

The walls aren’t necessarily like the walls of a room. Instead, they are more like barriers. And, they could help explain an intriguing part of space that has left astronomers scratching their heads for quite a while.

BGR.

Scientists may have found an explanation for the invisible walls in space that hold galaxies in orbit around larger galaxies.

Continue reading “Mysterious invisible walls may have been discovered in outer space” | >

Physicists from Paderborn University have developed a novel concept for generating individual photons—tiny particles of light that make up electromagnetic radiation—with tailored properties, the controlled manipulation of which is of fundamental importance for photonic quantum technologies. The findings have now been published in the journal Nature Communications.

Professor Artur Zrenner, head of the “nanostructure optoelectronics” research group, explains how tailored desired states have so far posed a challenge: “Corresponding sources are usually based on light emissions from individual semiconductor quantum emitters, which generate the photons. Here, the properties of the emitted photons are defined by the fixed properties of the quantum emitter, and can therefore not be controlled with full flexibility.”

To get around the problem, the scientists have developed an all-optical, non-linear method to tailor and control single photon emissions. Based on this concept, they demonstrate laser-guided energy tuning and polarization control of photons (i.e., the light frequency and direction of oscillation of electromagnetic waves).

Read more | >

A team of Cornell University engineers developed a new microscopy technique that’s powerful enough to spot an individual atom in three dimensions — and create an image so clear that the only blurriness comes from the movement of that atom itself.

The technique, which according to the study published Thursday in the journal Science relies on an electron microscope coupled with sophisticated 3D reconstruction algorithms, doesn’t just set a new record in atom resolution. The researchers even say this might be as good as microscopy gets.

“This doesn’t just set a new record,” lead author and Cornell engineer David Muller said in a press release. “It’s reached a regime which is effectively going to be an ultimate limit for resolution. We basically can now figure out where the atoms are in a very easy way. This opens up a whole lot of new measurement possibilities of things we’ve wanted to do for a very long time.”

Read more | >

A team of researchers from China, Germany and the U.S. has developed a way to create a less fragile diamond. In their paper published in the journal Nature, the group describes their approach to creating a paracrystalline diamond and possible uses for it.

Prior research has shown that diamond is the hardest known material but it is also fragile—despite their hardness, can be easily cut or even smashed. This is because of their ordered atomic structure. Scientists have tried for years to synthesize diamonds that retain their hardness but are less fragile. The team has now come close to achieving that goal.

Currently, the way to create diamonds is to place a carbon-based material in a vice-like device where it is heated to very high temperatures while it is squeezed very hard. In this new effort, the researchers have used the same approach to create a less ordered type of diamond but have added a new twist—the carbon-based material was a batch of fullerenes, also known as buckyballs ( arranged in a hollow spherical shape). They heated the material to between 900 and 1,300 °C at pressures of 27 to 30 gigapascals. Notably, the pressure exerted was much lower than is used to make commercial diamonds. During processing, the spheres were forced to collapse, and they formed into transparent paracrystalline diamonds which could be extracted at room temperature.

Read more | >

Scientists at the Max Planck Institute for the Science of Light (MPL) and Max-Planck-Zentrum für Physik und Medizin (MPZPM) in Erlangen present a large step forward in the characterization of nanoparticles. They used a special microscopy method based on interfereometry to outperform existing instruments. One possible application of this technique may be to identify illnesses.

Nanoparticles are everywhere. They are in our body as , lipid vesicles, or viruses. They are in our drinking water in the form of impurities. They are in the air we breath as pollutants. At the same time, many drugs are based on the delivery of , including the vaccines we have recently been given. Keeping with the pandemics, quick tests used for the detection the SARS-Cov-2 are based on nanoparticles too. The red line, which we monitor day by day, contains myriads of gold nanoparticles coated with antibodies against proteins that report infection.

Technically, one calls something a nanoparticle when its size (diameter) is smaller than one micrometer. Objects of the order of one micrometer can still be measured in a normal microscope, but particles that are much smaller, say smaller than 0.2 micrometers, become exceedingly difficult to measure or characterize. Interestingly, this is also the size range of viruses, which can become as small as 0.02 micrometers.

Read more | >

Computational detective work by U.S. and German physicists has confirmed that cerium zirconium pyrochlore is a 3D quantum spin liquid.

Despite the name, quantum spin liquids are solid materials in which quantum entanglement and the geometric arrangement of atoms frustrate the natural tendency of electrons to magnetically order themselves in relation to one another. The in a quantum spin liquid is so severe that electrons fluctuate between quantum magnetic states no matter how cold they become.

Theoretical physicists routinely work with quantum mechanical models that manifest quantum spin liquids, but finding convincing evidence that they exist in actual physical materials has been a decades-long challenge. While a number of 2D or 3D materials have been proposed as possible quantum spin liquids, Rice University physicist Andriy Nevidomskyy has said there’s no established consensus among physicists that any of them qualify.

Read more | >

Nestled 30 feet underground in Menlo Park, California, a half-mile-long stretch of tunnel is now colder than most of the universe. It houses a new superconducting particle accelerator, part of an upgrade project to the Linac Coherent Light Source (LCLS) X-ray free-electron laser at the Department of Energy’s SLAC National Accelerator Laboratory.

Crews have successfully cooled the accelerator to minus 456 degrees Fahrenheit—or 2 Kelvin—a temperature at which it becomes superconducting and can boost electrons to high energies with nearly zero energy lost in the process. It is one of the last milestones before LCLS-II will produce X-ray pulses that are 10,000 times brighter, on average, than those of LCLS and that arrive up to a million times per second—a world record for today’s most powerful X-ray light sources.

“In just a few hours, LCLS-II will produce more X-ray pulses than the current laser has generated in its entire lifetime,” says Mike Dunne, director of LCLS. “Data that once might have taken months to collect could be produced in minutes. It will take X-ray science to the next level, paving the way for a whole new range of studies and advancing our ability to develop revolutionary technologies to address some of the most profound challenges facing our society.”

Read more | >