Physicists discover a new switch for superconductivity

 

Under certain conditions—usually exceedingly cold ones—some materials shift their structure to unlock new, superconducting behavior. This structural shift is known as a "nematic transition," and physicists suspect that it offers a new way to drive materials into a superconducting state where electrons can flow entirely friction-free.

But what exactly drives this transition in the first place? The answer could help scientists improve existing superconductors and discover new ones.

Now, MIT physicists have identified the key to how one class of superconductors undergoes a nematic transition, and it's in surprising contrast to what many scientists had assumed.

The physicists made their discovery studying iron selenide (FeSe), a two-dimensional material that is the highest-temperature iron-based superconductor. The material is known to switch to a superconducting state at temperatures as high as 70 kelvins (close to -300 degrees Fahrenheit). Though still ultracold, this transition temperature is higher than that of most superconducting materials.

The higher the temperature at which a material can exhibit superconductivity, the more promising it can be for use in the real world, such as for realizing powerful electromagnets for more precise and lightweight MRI machines or high-speed, magnetically levitating trains.

For those and other possibilities, scientists will first need to understand what drives a nematic switch in high-temperature superconductors like iron selenide. In other iron-based superconducting materials, scientists have observed that this switch occurs when individual atoms suddenly shift their magnetic spin toward one coordinated, preferred magnetic direction.

But the MIT team found that iron selenide shifts through an entirely new mechanism. Rather than undergoing a coordinated shift in spins, atoms in iron selenide undergo a collective shift in their orbital energy. It's a fine distinction, but one that opens a new door to discovering unconventional superconductors.

"Our study reshuffles things a bit when it comes to the consensus that was created about what drives nematicity," says Riccardo Comin, the Class of 1947 Career Development Associate Professor of Physics at MIT. "There are many pathways to get to unconventional superconductivity. This offers an additional avenue to realize superconducting states."

Comin and his colleagues published their results in a study appearing in Nature Materials. Co-authors at MIT include Connor Occhialini, Shua Sanchez, and Qian Song, along with Gilberto Fabbris, Yongseong Choi, Jong-Woo Kim, and Philip Ryan at Argonne National Laboratory.

                                          International Research Conference on High Energy Physics

Submit Your Conference Abstract: https://x-i.me/hepcon

Submit Your Award Nomination: https://x-i.me/hepnom

 

Get Connected Here:

==================

Facebook : https://x-i.me/yHa5

Twitter : https://twitter.com/Psciencefather

Pinterest : https://in.pinterest.com/victoriaanisa1/

Blog : https://physicscience23.blogspot.com/

Instagram : https://www.instagram.com/victoriaanisa1/

                                            tumblr : https://www.tumblr.com/blog/high-energy-physics  

The Best Particle Collider in the World

 

Recently astronomers caught a strange mystery: extremely high-energy particles spitting out of the surface of the Sun when it was relatively calm. Now a team of theorists have proposed a simple solution to the mystery. We just have to look a little bit under the surface. In 2022 the High Altitude Water Cherenkov (HAWC) observatory detected a flash of extremely high gamma ray radiation coming from the disk of the sun. To generate that kind of radiation required a particle with TeV energies slamming into another particle. This observation came on the heels of over six years worth of observations with the Fermi Large Area Telescope in orbit of the Earth. That telescope found significant gamma ray detections also coming from the Sun. Those detections were of lower energy than the HAWC results, but pointed in the same general direction. What was especially surprising about these observations was that these remarkably high-energy particles seemed to be emitted from the Sun when it was in a relatively quiet state. Occasionally solar storms and flares rip across the surface of the Sun, and naturally these generate enormous amounts of energies which can easily create high-energy particles. But when the Sun is quiet it’s much harder to identify a sufficiently large source of energy to power these kinds of processes.

In a new paper a team of theoretical astrophysicists have proposed a solution. It seems that the mystery of the high-energy particles coming from the Sun is only skin deep. The photosphere is the outermost visible layer of the Sun which emits the light that we can see. The researchers confirmed earlier calculations that there is no process in the photosphere or just above it that has the required energy. But the layer just below the photosphere, known as the chromosphere, can have enough energy. The turbulent motions of plasma within the chromosphere and the complex tangled magnetic fields found there can take particles to very high energy levels. The particles themselves are cosmic rays, which rain into the solar system from the wider universe. The cosmic rays enter the Sun and reach the chromosphere, where they get tangled up with the strong and complex magnetic fields there. They get accelerated to incredibly high energies and then spit back out of the Sun. Once free they slam into a random proton that happens to be hanging out near the surface of the Sun, which generates a flash of gamma ray radiation.

International Research Conference on High Energy Physics

Submit Your Conference Abstract: https://x-i.me/hepcon

Submit Your Award Nomination: https://x-i.me/hepnom

 

Get Connected Here:

==================

Facebook : https://x-i.me/yHa5

Twitter : https://twitter.com/Psciencefather

Pinterest : https://in.pinterest.com/victoriaanisa1/

Blog : https://physicscience23.blogspot.com/

Instagram : https://www.instagram.com/victoriaanisa1/

                                            tumblr : https://www.tumblr.com/blog/high-energy-physics  

Scientists Use Giant Atom Smasher in Search for Magnetic Monopoles

 

Scientists are using the intense magnetic fields generated by the world's largest atom smasher to search for one of the most elusive particles of all -- the magnetic monopole, a hypothetical particle with either a "north" or "south" magnetic charge, but which has never been seen.

A study published this month in the journal Nature describes the latest experiments with the MoEDAL instrument -- the Monopole and Exotics Detector at the Large Hadron Collider (LHC) -- which was installed in 2015. So far, it's never found any monopoles, but that might be because previous MoEDAL experiments looked for monopoles created in collisions between particles like protons and neutrons. 

However, "we realized there is a different mechanism for producing monopoles, not based on collisions of elementary particles," said Arttu Rajantie, a professor of theoretical physics at Imperial College London and a co-author of the study.

Instead, the latest experiments look for monopoles created by what's called the "Schwinger mechanism" in powerful magnetic fields. If monopoles exist, the mechanism would create them as pairs of particles with opposite poles -- one with a "north" magnetic field and the other with a "south" magnetic field, but moving in opposite directions and otherwise completely independent of each other. 

The mechanism is named after the American Nobel Prize-winning physicist Julian Schwinger, who in 1951 theorized that strong electric fields would produce electrically charged particles in the same way. Electric fields have since been shown to produce electron-positron pairs -- so physicists hypothesize a strong magnetic field will similarly create pairs of monopoles, the magnetic counterparts of electrons and positrons.

Crucially, the Schwinger mechanism lets scientists confidently calculate how many monopoles of a given mass and magnetic charge would be produced by a magnetic field of known strength. Rajantie led the calculations for the latest study. While the experiments once again didn't find any monopoles, the calculations have enabled the team to narrow down their search by ruling out the possibility that monopoles have very low mass or less than a certain magnetic charge.

The study's lead author, University of Alabama particle physicist Igor Ostrovskiy, said magnetic monopoles feature in several theories that seek to go beyond the Standard Model of particle physics, which describes three of the four known fundamental forces and all of the known elementary particles (currently there are 31, including the Higgs boson). 

"There are strong reasons to believe that the Standard Model of physics is not the whole story," he said in an email. Combined with other evidence, there's "a good indication that monopoles may exist and be worth searching for."

But monopoles only exist in theories so far. The magnetism we take for granted -- it sticks magnets to fridges and generates electricity in turbines -- is caused not by monopoles but either by the quantum spin of subatomic particles in a material or by electric currents. But those processes always create a magnetic dipole -- a magnet with a north pole and a south pole that are impossible to separate.

The technological consequences of discovering monopoles can't be foreseen, but it would have "a transformative impact on physics," Ostrovskiy said. "It would confirm that there are laws of nature not captured by the current ruling theory of physics."

The researchers examined the MoEDAL detectors after the LHC's 2018 run of billions of lead nuclei collisions, which was conducted mainly so physicists could study the quark-gluon plasma created when heavy ions smash into each other.

Rajantie explained that the occasional near-misses of the lead nuclei in the LHC briefly created the most powerful magnetic fields on Earth, and possibly anywhere -- the fields were 10,000 times stronger than those on the surface of spinning neutron stars called magnetars. And although they only lasted less than a septillionth of a second, they were also about 10 million times stronger than the weakest magnetic fields needed by the Schwinger mechanism, so they would have produced monopoles -- that is, if monopoles exist.

The team hoped to trap the stable monopoles in the MoEDAL instrument's detector, which consists of 1,700-pound (800 kilogram) aluminum blocks. The blocks were dismantled after the run and passed through a superconducting magnetic loop to verify if any monopoles had been found.

But they weren't found -- and thanks to the predictions of the Schwinger mechanism, the scientists have now ruled out the possibility that monopoles are lighter than about 75 times the mass of a proton, with fewer than three base units of magnetic charge. Their next step will be to repeat the experiments, after modifying the MoEDAL instrument to detect heavier magnetic monopoles with greater magnetic charges.

International Research Conference on High Energy Physics

Submit Your Conference Abstract: https://x-i.me/hepcon

Submit Your Award Nomination: https://x-i.me/hepnom

 

Get Connected Here:

==================

Facebook : https://x-i.me/yHa5

Twitter : https://twitter.com/Psciencefather

Pinterest : https://in.pinterest.com/victoriaanisa1/

Blog : https://physicscience23.blogspot.com/

Instagram : https://www.instagram.com/victoriaanisa1/

                                            tumblr : https://www.tumblr.com/blog/high-energy-physics  

Theoretical discovery: A new path for quantum physics to control chemical reactions

 

Controlling chemical reactions to generate new products is one of the biggest challenges in chemistry. Developments in this area impact industry, for example, by reducing the waste generated in the manufacture of construction materials or by improving the production of catalysts to accelerate chemical reactions.

For this reason, in the field of polariton chemistry—which uses tools of chemistry and quantum optics—in the last 10 years different laboratories around the world have developed experiments in optical cavities to manipulate the chemical reactivity of molecules at room temperature, using electromagnetic fields. Some have succeeded in modifying chemical reactions products in organic compounds, but to date, and without relevant advances in the last two years, no research team has been able to come up with a general physical mechanism to describe the phenomenon and to reproduce it to obtain the same measurements in a consistent manner. Now a team of researchers from Universidad de Santiago (Chile), part of the Millennium Institute for Research in Optics (MIRO), led by principal investigator Felipe Herrera, and the laboratory of the chemistry division of the US Naval Research Laboratory, (United States), led by researcher Blake Simpkins, for the first time report the manipulation of the formation rate of urethane molecules in a solution contained inside an infrared cavity. The discovery was published on June 16, 2023, in the journal Science and proves, for the first time, both theoretically and experimentally, that it is possible to selectively modify the reactivity of certain bonds in a chemical reaction at room temperature in a liquid solvent, through the influence of the electromagnetic field vacuum in a narrow range of infrared frequencies. "This theoretical discovery improves our fundamental understanding of the phenomenon over other models that merely explain partial aspects of the experimental observations or simply refute the experimental evidence entirely," says researcher Felipe Herrera.

New scientific scope for molecule manipulation 

Why is it so hard to control chemical reactions? When chemical reactions occur, the bonds that unite the atoms in a molecule break and rearrange, forming new substances known as products. For this process to occur, energy is often needed, and several physicochemical principles dating from the 19th century have helped us understand how these energy transfer occurs according to the laws of thermodynamics. There are also principles of reactivity based on the structures of molecules, such as those proposed by Eyring, Evans and Polanyi in 1935, widely used in all areas of chemistry. These basic principles imply that each reaction between two molecules is independent of the other chemical reactions that may occur in a solution. "That is very valid in almost all situations studied in eighty years and more, but the electromagnetic vacuum creates correlations between the different chemical reactions that happen within the volume of the cavity, and those correlations created by the electromagnetic field, in principle make the traditional assumptions of chemical reactivity questionable," explains Felipe Herrera. "The experimental contribution of this study is the confirmation of the modification of the reaction rates through the interaction with the vacuum of the electromagnetic field confined inside the cavity, using a well-studied chemical reaction, and with more significant changes than those found with other types of reactions. In the theoretical part, the contribution is the fact that by modifying the dynamics of the chemical bonds that mainly participate in the reaction, through the infrared vacuum, it is possible to control the products," adds Johan Triana, a postdoctoral fellow at MIRO and the University of Santiago who participated in the creation of the mathematical model and the numerical calculations for the description of the molecular system.

Reproducing and interpreting measurements 

The research started in 2020, when the then postdoctoral fellow at the US Naval Research Laboratory, now a professor at Bilkent University, Dr. Wonmi Ahn, performed the first experiments. In 2021 Blake Simpkins prepared new samples to ensure that the measurements were reproducible and improved the liquid cells where the chemical reactions occur. In the middle of that year, researcher Felipe Herrera began to have regular meetings with Simpkins to investigate possible theoretical answers to support the results obtained. "We decided to start from scratch and build a theory that takes all the physical aspects of quantum optics into consideration, but that under specific conditions reduces to the standard reactivity theory of theoretical chemistry," explains USACH professor Felipe Herrera. The result of the process is the publication "Modification of ground-state chemical reactivity via light-matter coherence in infrared cavities," led by Simpkins (US Naval Research Laboratory) and Herrera (MIRO, Universidad de Santiago de Chile), with the participation of researcher Wonmi Ahn, (Bilkent University, Turkey), researcher Johan Triana and Ph.D. student Felipe Recabal, both part of the Molecular Quantum Technology group of MIRO, at USACH. This first work opens new possibilities and scientific challenges, Dr. Herrera explains, "We need to develop a sufficiently simple and general theoretical and mathematical framework that any researcher in the world can use to interpret their experiments and hopefully design new types of measurements that no one has yet visualized." In this sense, Herrera reflects on his ambitions as a scientist moving across physics and chemistry: "It would be nice to build a consistent theory that unifies two of the most successful disciplines in modern science: chemical kinetics and quantum physics."

International Research Conference on High Energy Physics

Submit Your Conference Abstract: https://x-i.me/hepcon

Submit Your Award Nomination: https://x-i.me/hepnom

 

Get Connected Here:

==================

Facebook : https://x-i.me/yHa5

Twitter : https://twitter.com/Psciencefather

Pinterest : https://in.pinterest.com/victoriaanisa1/

Blog : https://physicscience23.blogspot.com/

Instagram : https://www.instagram.com/victoriaanisa1/

                                            tumblr : https://www.tumblr.com/blog/high-energy-physics  

SPbPU Is Now An Official Participant In Unique Experiments At The NICA Hadron Collider

 

Peter the Great St. Petersburg Polytechnic University has become a member of the international MPD and SPD colliders of the NICA complex of the Joint Institute for Nuclear Research (Dubna). The Nuclotron-based Ion Collider fAcility (NICA) is a new acceleration complex being built at the Joint Institute for Nuclear Research to study the properties of dense baryonic matter. Scientists from more than 20 countries are participating in this project. In fact, after the NICA collider is launched, JINR scientists will be able to recreate under laboratory conditions the special state of matter in which our Universe was in the first moments after the Big Bang — the quark-gluon plasma.

SPbPU became an official participant in unique experiments at the NICA hadron collider

Scientists from SPbPU are taking part in experiments at the collider’s two main facilities, the MPD (Multi-Purpose Detector) and the SPD (Spin Physics Detector). The MPD is designed for experiments in nuclear physics related to the study of particle production in proton-proton, proton-nucleus, and nucleus-nucleus collisions. SPD (Spin Physics Detector) is intended for experiments in spin physics.

SPbPU, having extensive experience in particle physics, high-energy physics, detector technologies, as well as in the development of systems for the collection, processing and analysis of large data, will perform the following activities as part of the SPD and MPD experiments:

Development of specialized software for specific tasks. In particular, Montecarlian modeling for research and optimization of physical signals and background events

Physics of 3D parton distributions of protons and nuclei and particle correlations

Machine learning for solving SPD and MPD plant problems

Development of electronic modules for the SPD data acquisition system and interface with NICA.

The collider can recreate the special state of matter that our Universe was in in the first moments after the Big Bang

Currently, the research team consists of 17 people, including seven students. The team is headed by Professor of the Higher School of Fundamental Physical Research at the Institute of Physics and Mechanics of SPbPU Yaroslav Berdnikov, Doctor of Physics and Mathematics. It is assumed that in the future the number of participants in the group may be increased.

International Research Conference on High Energy Physics

Submit Your Conference Abstract: https://x-i.me/hepcon

Submit Your Award Nomination: https://x-i.me/hepnom

 

Get Connected Here:

==================

Facebook : https://x-i.me/yHa5

Twitter : https://twitter.com/Psciencefather

Pinterest : https://in.pinterest.com/victoriaanisa1/

Blog : https://physicscience23.blogspot.com/

Instagram : https://www.instagram.com/victoriaanisa1/

                                            tumblr : https://www.tumblr.com/blog/high-energy-physics  

Exploring the Cosmos: A Journey into Cosmology

Introduction: Welcome to our cosmology blog, where we embark on a captivating journey into the depths of the universe. Join us as we unravel the mysteries of cosmic origins, delve into the nature of space and time, and explore the remarkable phenomena that shape our cosmic landscape.

The Big Bang and the Birth of the Universe: Discover the profound implications of the Big Bang theory, the explosive event that marked the beginning of our universe. Explore the evidence supporting this cosmic birth and learn about the cosmic microwave background radiation, a remarkable echo of the universe's earliest moments. Dark Matter and Dark Energy: Dive into the mysterious realms of dark matter and dark energy, two invisible forces that dominate the universe. Learn about their enigmatic nature, their roles in shaping the cosmic structure, and the ongoing efforts to understand their origins and properties. Galaxies: Building Blocks of the Universe: Uncover the captivating world of galaxies, cosmic cities composed of billions of stars. Explore their diverse shapes, sizes, and formations, and gain insights into the remarkable interplay between gravity, gas, and stellar evolution that shapes their existence. Black Holes: Cosmic Monsters: Plunge into the depths of black holes, the gravitational beasts that warp space and time. Discover the different types of black holes, from stellar remnants to supermassive ones at the centers of galaxies, and learn about their mesmerizing effects on surrounding matter and light. The Cosmic Web: A Tapestry of Connections: Unravel the intricate cosmic web that connects galaxies across vast distances. Explore the role of dark matter in forming this cosmic scaffolding and understand how its structure influences the evolution of galaxies and the flow of cosmic energy. Cosmic Inflation: The Rapid Expansion: Learn about cosmic inflation, a period of exponential expansion in the early universe. Delve into the theories behind this rapid growth and its implications for the large-scale structure of the cosmos. Frontiers of Cosmology: Stay up to date with the latest discoveries and advancements in the field of cosmology. Explore ongoing research projects, space missions, and telescopes that push the boundaries of our understanding of the universe. Conclusion: Come along on this cosmic journey as we delve into the wonders of cosmology. From the grandeur of the Big Bang to the intricate web of galaxies, there is an infinite universe of knowledge waiting to be explored. Join us in unraveling the mysteries of the cosmos and gaining a deeper appreciation for our place in the vastness of space.

International Research Conference on High Energy Physics

Submit Your Conference Abstract: https://x-i.me/hepcon

Submit Your Award Nomination: https://x-i.me/hepnom

 

Get Connected Here:

==================

Facebook : https://x-i.me/yHa5

Twitter : https://twitter.com/Psciencefather

Pinterest : https://in.pinterest.com/victoriaanisa1/

Blog : https://physicscience23.blogspot.com/

Instagram : https://www.instagram.com/victoriaanisa1/

                                                    tumblr : https://www.tumblr.com/blog/high-energy-physics