https://phys.org/news/2021-05-scientist ... antum.htmlMay 18, 2021
Scientists believe that individual light particles, or photons, are ideally suited for sending quantum information. Encoded with quantum data, they could literally transfer information at the speed of light. However, while photons would make for great carriers because of their speed, they don't like to interact with each other, making it difficult to achieve quantum entanglement.
An international research team from NUST MISIS, Russian Quantum Center, the Ioffe Institute St. Petersburg and Karlsruhe Institute of Technology has obtained experimental evidence for effective interaction between microwave photons via superconductive qubits for the first time. The study, published in npj Quantum Materials, may be a step toward the implementation of a long-living quantum memory and the development of commercial quantum devices.
https://phys.org/news/2021-05-evidence- ... ld-2d.htmlMay 24, 2021
A team of researchers working at the Institut für Laserphysik, Universität Hamburg, has found evidence of superfluidity in an extremely cold 2D gas of fermions. In their paper published in the journal Science, the group describes their work with a 2D Fermi gas and what they learned from it.
One of the big challenges remaining in physics is to understand the factors at play with superconductors operating at high temperatures. One approach to achieving that goal involves studying superfluidity in materials. Superfluids are materials that can flow without viscosity—though only at speeds lower than their critical velocity. In this new effort, the researchers looked at the possibility of a 2D Fermi gas as a superfluid. Prior research has shown that 3D Fermi gases can exhibit superfluid characteristics, and theory has suggested that 2D Fermi gasses could, as well—but until now, it had never been demonstrated.
The experiment and demonstration by the team in Germany began with the researchers isolating approximately 6,000 lithium-6 ions creating a Fermi gas. They then used optical and magnetic equipment to cool the gas down to near absolute zero—this held the ions firmly in place. The researchers then created a "box" for the atoms by suspending them in a lattice created using two blue lasers. This allowed for confining the atoms into a 2D configuration. The researchers then forced the gas through the lattice using dual red laser beams using an interference pattern. Changing the frequency of the lasers allowed the researchers to vary the speed at which the gas was moved through the lattice.
https://scitechdaily.com/new-quantum-ma ... roperties/May 24, 2021
A research team from TU Wien together with US research institutes came across a surprising form of ‘quantum criticality’; this could lead to a design concept for new materials.
In everyday life, phase transitions usually have to do with temperature changes — for example, when an ice cube gets warmer and melts. But there are also different kinds of phase transitions, depending on other parameters such as magnetic field. In order to understand the quantum properties of materials, phase transitions are particularly interesting when they occur directly at the absolute zero point of temperature. These transitions are called “quantum phase transitions” or a “quantum critical points.”
Such a quantum critical point has now been discovered by an Austrian-American research team in a novel material, and in an unusually pristine form. The properties of this material are now being further investigated. It is suspected that the material could be a so-called Weyl-Kondo semimetal, which is considered to have great potential for quantum technology due to special quantum states (so-called topological states). If this proves to be true, a key for the targeted development of topological quantum materials would have been found. The results were found in a cooperation between TU Wien, Johns Hopkins University, the National Institute of Standards and Technology (NIST) and Rice University and has now been published in the journal Science Advances.
https://phys.org/news/2021-05-rice-phys ... netic.htmlMay 25, 2021
Sometimes things are a little out of whack, and it turns out to be exactly what you need.
That was the case when orthoferrite crystals turned up at a Rice University laboratory slightly misaligned. Those crystals inadvertently became the basis of a discovery that should resonate with researchers studying spintronics-based quantum technology.
Rice physicist Junichiro Kono, alumnus Takuma Makihara and their collaborators found an orthoferrite material, in this case yttrium iron oxide, placed in a high magnetic field showed uniquely tunable, ultrastrong interactions between magnons in the crystal.
Orthoferrites are iron oxide crystals with the addition of one or more rare-earth elements.
https://phys.org/news/2021-05-physicist ... nnest.html
by Elizabeth A. Thomson, Materials Research Laboratory, Massachusetts Institute of Technology
Part of the resonant inelastic x-ray scattering (RIXS) instrument at Diamond Light Source (UK) that was used to uncover secrets of the world’s thinnest superconductor. Credit: Diamond Light Source
Physicists from across three continents report the first experimental evidence to explain the unusual electronic behavior behind the world's thinnest superconductor, a material with myriad applications because it conducts electricity extremely efficiently. In this case the superconductor is only an atomic layer thick.
The work, led by an MIT professor and a physicist at Brookhaven National Laboratory, was possible thanks to new instrumentation available at only a few facilities in the world. The resulting data could help guide the development of better superconductors. These in turn could transform the fields of medical diagnostics, quantum computing, and energy transport, which all use superconductors.
Researchers at Cornell University have snapped the clearest images of atoms ever taken. Aided by new noise-reducing algorithms, the images are of such high resolution that, the team says, they almost reach the ultimate limit possible.
The images were taken of atoms in a praseodymium orthoscandate (PrScO3) crystal, zoomed in 100 million times. The atoms can be clearly seen as bright dots, surrounded by red “clouds”, which, according to the researchers, are blurring created by the jiggling of the atoms themselves.
The Large Hadron Collider’s claim to fame is its ability to unveil elusive subatomic particles. But there’s one class of particle that it had never directly detected, even though it produces them in abundance. Neutrinos, minute elementary particles, interact so little with matter that they sail through the particle accelerator’s massive detectors unnoticed (SN: 4/8/21).
Now, in a proof-of-concept experiment, the first evidence for neutrino interactions at the LHC has been spotted, researchers with the FASER collaboration report May 13 at arXiv.org. The technique could open up a window to neutrinos at energies for which the particles’ interactions are poorly understood.
https://www.cbsnews.com/news/exploring- ... me-travel/May 30, 2021
Be honest: who hasn't wanted to hit fast-forward or rewind on life? For as long as there has been a concept of time, that urge to break the bonds of time is, well, timeless.
"The idea of time travel is actually as old as civilization itself," said Lisa Yaszek, a professor of science fiction studies at Georgia Tech. "We see the very first stories in the 'Mahābhārata,' the great Indian epic, in 400 B.C.E., so they're nearly 2,500 years old."
According to Yaszek, early time travel stories, like Washington Irving's "Rip Van Winkle" or Mark Twain's "A Connecticut Yankee in King Arthur's Court," were full of magic, not science. But, "As we moved into an industrial culture, suddenly we had trains that had to move on schedule from station to station, and ships that had to cross great bodies of water and make it into docks at certain time. We had to make sure that humans in different parts of the world were telling time in the same ways. And I think that was really exciting – we felt like we suddenly did have a little control over time."
https://phys.org/news/2021-06-lasers-ca ... gabit.htmlWith the massive proliferation of data-heavy services, including high-resolution video streaming and conferencing, cloud services infrastructure growth in 2021 is expected to reach a 27% CAGR. Consequently, while 400 gigabit ethernet (GbE) is currently enjoying widespread deployment, 800 GbE is poised to rapidly follow to address these bandwidth demands.
One approach to 800 GbE is to install eight 100 gigabit per second (Gbps) optical interfaces or lanes. As an alternative to reduce the hardware count, increase reliability, and lower cost, a team of researchers at Lumentum developed an optical solution that uses four 200 Gbps wavelength lanes to reach 800 GbE.
Syunya Yamauchi, a principal optical engineer at Lumentum, will present the optimized design during a session at the Optical Fiber Communication Conference and Exhibition (OFC), being held virtually from 06-11 June, 2021.
https://phys.org/news/2021-06-silicon-e ... nergy.htmlJune 4, 2021
A team led by Carnegie's Thomas Shiell and Timothy Strobel developed a new method for synthesizing a novel crystalline form of silicon with a hexagonal structure that could potentially be used to create next-generation electronic and energy devices with enhanced properties that exceed those of the "normal" cubic form of silicon used today.
Their work is published in Physical Review Letters.
Silicon plays an outsized role in human life. It is the second most abundant element in the Earth's crust. When mixed with other elements, it is essential for many construction and infrastructure projects. And in pure elemental form, it is crucial enough to computing that the longstanding technological hub of the U.S.—California's Silicon Valley—was nicknamed in honor of it.
Like all elements, silicon can take different crystalline forms, called allotropes, in the same way that soft graphite and super-hard diamond are both forms of carbon. The form of silicon most commonly used in electronic devices, including computers and solar panels, has the same structure as diamond. Despite its ubiquity, this form of silicon is not actually fully optimized for next-generation applications, including high-performance transistors and some photovoltaic devices.
According to a report by Explica.co, The Station of Extreme Light, which China has been developing in Shanghai since 2018, has made significant progress in its goal of manufacturing lasers so powerful by 2023 that they could break through empty space and create matter.
The Extreme Light Station (SEL) is a laser installation designed to produce a laser with 100 petawatts (PW) of maximum power (one petawatt equals one thousand trillion watts), a goal that is expected to be achieved within two years.
Once completed, the laser will be the most powerful on Earth, with a power 10,000 times greater than that of all the electrical networks in the world combined and with an intensity 10 trillion times greater than that of sunlight, the report said.
The laser will be powerful enough to produce matter and antimatter directly from the vacuum of space, allowing us to observe in a terrestrial laboratory the same process that supposedly gave rise to the universe.
This technology is based on the fact that a vacuum is never really empty: it is like a pond filled with pairs of electrons and positrons (particles of matter and antimatter) that occasionally emerge to the surface (existence), although they annihilate each other as soon as they are formed.
The cones in this image illustrate the equations of motion of electrons when an external magnetic field is applied to the bismuth alloy engineered for the study. Green lines and purple lines represent electrons that generate and absorb energy, respectively. Credit: Renee Ripley
Researchers have discovered a new electronic property at the frontier between the thermal and quantum sciences in a specially engineered metal alloy—and in the process identified a promising material for future devices that could turn heat on and off with the application of a magnetic "switch."
In this material, electrons, which have a mass in vacuum and in most other materials, move like massless photons or light—an unexpected behavior, but a phenomenon theoretically predicted to exist here. The alloy was engineered with the elements bismuth and antimony at precise ranges based on foundational theory.
Under the influence of an external magnetic field, the researchers found, these oddly behaving electrons manipulate heat in ways not seen under normal conditions. On both the hot and cold sides of the material, some of the electrons generate heat, or energy, while others absorb energy, effectively turning the material into an energy pump. The result: A 300% increase in its thermal conductivity.
Take the magnet away, and the mechanism is turned off.
Using an ultrafast transmission electron microscope, researchers from the Technion—Israel Institute of Technology have, for the first time, recorded the propagation of combined sound and light waves in atomically thin materials.
The experiments were performed in the Robert and Ruth Magid Electron Beam Quantum Dynamics Laboratory headed by Professor Ido Kaminer, of the Andrew and Erna Viterbi Faculty of Electrical & Computer Engineering and the Solid State Institute.
Single-layer materials, alternatively known as 2D materials, are in themselves novel materials, solids consisting of a single layer of atoms. Graphene, the first 2D material discovered, was isolated for the first time in 2004, an achievement that garnered the 2010 Nobel Prize. Now, for the first time, Technion scientists show how pulses of light move inside these materials. Their findings, "Spatiotemporal Imaging of 2D Polariton Wavepacket Dynamics Using Free Electrons," were published in Science.
https://newatlas.com/physics/charm-meso ... ntimatter/A subatomic particle has been found to switch between matter and antimatter, according to Oxford physicists analyzing data from the Large Hadron Collider. It turns out that an unfathomably tiny weight difference between two particles could have saved the universe from annihilation soon after it began.
Antimatter is kind of the “evil twin” of normal matter, but it’s surprisingly similar – in fact, the only real difference is that antimatter has the opposite charge. That means that if ever a matter and antimatter particle come into contact, they will annihilate each other in a burst of energy.
To complicate things, some particles, such as photons, are actually their own antiparticles. Others have even been seen to exist as a weird mixture of both states at the same time, thanks to the quantum quirk of superposition (illustrated most famously through the thought experiment of Schrödinger’s cat.) That means that these particles actually oscillate between being matter and antimatter.
https://phys.org/news/2021-06-modular-q ... ensor.htmlJune 11, 2021
A team of scientists at the University of Sussex have for the first time built a modular quantum brain scanner, and used it to record a brain signal. This is the first time a brain signal has been detected using a modular quantum brain sensor anywhere in the world. It's a major milestone for all researchers working on quantum brain imaging technology because modular sensors can be scaled up, like Lego bricks. The team have also connected two sensors like Lego bricks, proving that whole-brain scanning using this method is within reach—as detailed in their paper, which is published today in pre-print. This has not been possible with the currently commercially available quantum brain sensors from the United States.
These modular devices work like play bricks in that they can be connected together. This opens up the potential for whole-brain scanning using quantum technology, and potential advances for neurodegenerative diseases like Alzheimer's.
The device, which was built at the Quantum Systems and Devices laboratory at the university, uses ultra-sensitive quantum sensors to pick up these tiniest of magnetic fields to see inside the brain in order to map the neural activity.
The team applied the sensors to outside of a participant's scalp, close to the visual cortex of the brain. They asked the participant to open and close their eyes at 10–20 second intervals, and were able to detect a signal. This is a very simple action, but to see it happening inside the brain—from the outside—requires hugely sophisticated quantum technology.
To the human eye, most stationary objects appear to be just that—still, and completely at rest. Yet if we were handed a quantum lens, allowing us to see objects at the scale of individual atoms, what was an apple sitting idly on our desk would appear as a teeming collection of vibrating particles, very much in motion.
In the last few decades, physicists have found ways to super-cool objects so that their atoms are at a near standstill, or in their "motional ground state." To date, physicists have wrestled small objects such as clouds of millions of atoms, or nanogram-scale objects, into such pure quantum states.
Now for the first time, scientists at MIT and elsewhere have cooled a large, human-scale object to close to its motional ground state. The object isn't tangible in the sense of being situated at one location, but is the combined motion of four separate objects, each weighing about 40 kilograms. The "object" that the researchers cooled has an estimated mass of about 10 kilograms, and comprises about 1x1026, or nearly 1 octillion, atoms.
While many physicists have predicted the existence of dark matter, a type of matter that does not absorb, reflect or emit light, so far no one has been able to observe it experimentally or determine its fundamental nature. Light primordial black holes (PBHs), black holes the formed in the early universe, are among the most promising dark matter candidates. However, the existence of these black holes has not yet been confirmed.
Researchers at University of Amsterdam and University of California- Santa Cruz have recently carried out a study aimed at improving existing constraints on the allowed parameter space of PBHs as dark matter. In their paper, published in Physical Review Letters, they also propose a possible method that could be used to directly detect Hawking radiation in dark matter dense regions and potentially enable the discovery of PBH dark matter.
