Daily Archives: August 14, 2023

Exploring the Intricacies of Quantum Integrated Circuits: The Future of Technology?

Quantum integrated circuits, a term that may sound like its straight out of a science fiction novel, are rapidly becoming a reality. This fascinating technology, which combines the principles of quantum mechanics with the functionality of integrated circuits, is poised to revolutionize the world of technology as we know it.

Quantum mechanics, the branch of physics that deals with the smallest particles in the universe, has long been a subject of intrigue and mystery. Its a world where particles can exist in multiple places at once, where they can be both waves and particles, and where they can be entangled in such a way that the state of one particle can instantly affect the state of another, no matter how far apart they are.

Integrated circuits, on the other hand, are a cornerstone of modern technology. They are the brains of our computers, smartphones, and countless other devices, enabling them to process information and perform complex tasks.

The marriage of these two fields in quantum integrated circuits is a groundbreaking development. These circuits use quantum bits, or qubits, which can exist in multiple states at once, rather than the binary bits used in traditional computing. This allows them to process information in a fundamentally different way, potentially making them exponentially more powerful than even the most advanced classical computers.

The potential applications of quantum integrated circuits are vast and varied. They could revolutionize fields such as cryptography, enabling the creation of codes that are virtually unbreakable. They could also dramatically speed up complex calculations in fields such as drug discovery and climate modeling, potentially leading to major breakthroughs.

However, the development of quantum integrated circuits is not without its challenges. Quantum systems are extremely delicate and can be easily disrupted by their environment, a problem known as decoherence. This makes them difficult to scale up and maintain over long periods.

Despite these challenges, progress is being made. Researchers around the world are developing new techniques to create and manipulate qubits, and to protect them from decoherence. Companies like Google, IBM, and Microsoft are investing heavily in quantum computing research, and there are even startups dedicated to developing quantum integrated circuits.

The future of quantum integrated circuits is still uncertain. There are many technical hurdles to overcome, and it may be years or even decades before they become commonplace. However, the potential rewards are enormous. If successful, they could usher in a new era of technological innovation, transforming everything from healthcare to finance to artificial intelligence.

In conclusion, the world of quantum integrated circuits is a fascinating one, filled with both promise and challenges. Its a world where the laws of physics as we know them are turned on their head, where the impossible becomes possible, and where the future of technology may well be written. Whether or not they become the next big thing, one thing is certain: they are a testament to the boundless potential of human ingenuity and the relentless pursuit of knowledge.

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The Fascinating World of Quantum Integrated Circuits: The Next Big ... - Fagen wasanni

A recent study reveals that the orbital motions of widely separated binary stars, or wide binaries, break down the standard model of gravity at low accelerations. Analyzing data from 26,500 wide binaries, researchers found that accelerations below one nanometer per second squared deviate from Newtons and Einsteins gravitational laws.

A study on the orbital motions of wide binaries has uncovered evidence that standard gravity breaks down at low accelerations. This discovery aligns with a modified theory called MOND and challenges current concepts of dark matter. The implications for astrophysics, physics, and cosmology are profound, and the results have been acknowledged as a significant discovery by experts in the field.

A new study reports conclusive evidence for the breakdown of standard gravity in the low acceleration limit, stemming from a verifiable analysis of the orbital motions of long-period, widely separated binary stars. These stars are commonly referred to as wide binaries in astronomy and astrophysics. The study was carried out by Kyu-Hyun Chae, professor of physics and astronomy at Sejong University in Seoul, and it used up to 26,500 wide binaries within 650 light years (LY), observed by the European Space Agencys Gaia space telescope.

For a significant improvement over other research, Chaes study concentrated on calculating the gravitational accelerations experienced by binary stars as a function of their separation or equivalently, the orbital period. This was achieved by a Monte Carlo deprojection of observed sky-projected motions to three-dimensional space.

Chae explains, From the start, it seemed clear to me that gravity could be most directly and efficiently tested by calculating accelerations because the gravitational field itself is an acceleration. My recent research experiences with galactic rotation curves led me to this idea. Galactic disks and wide binaries share some similarity in their orbits, though wide binaries follow highly elongated orbits while hydrogen gas particles in a galactic disk follow nearly circular orbits.

In addition, Chae calibrated the occurrence rate of hidden nested inner binaries at a benchmark acceleration, unlike other studies.

Left: A binary star system with a nested inner binary (credit: Wikipedia). Right: Gravitational anomaly at low acceleration observed in 20,000 wide binaries Credit: Kyu-Hyun Chae

The study reveals that when two stars orbit each other with accelerations lower than about one nanometer per second squared, they start to deviate from predictions by Newtons universal law of gravitation and Einsteins general relativity. For accelerations lower than approximately 0.1 nanometer per second squared, the observed acceleration is about 30 to 40 percent higher than the Newton-Einstein prediction. The significance is considerable, meeting the conventional criteria of 5 sigma for a scientific discovery. In a sample of 20,000 wide binaries within a distance limit of 650 LY, two independent acceleration bins respectively show deviations of over 5 sigma significance in the same direction.

Because the observed accelerations stronger than about 10 nanometers per second squared agree well with the Newton-Einstein prediction from the same analysis, the observed boost of accelerations at lower accelerations is a mystery. Intriguingly, this breakdown of the Newton-Einstein theory at weaker accelerations was suggested 40 years ago by theoretical physicist Mordehai Milgrom at the Weizmann Institute in Israel in a new theoretical framework called modified Newtonian dynamics (MOND) or Milgromian dynamics in current usage.

The boost factor of about 1.4 is correctly predicted by a MOND-type Lagrangian theory of gravity called AQUAL, proposed by Milgrom and the late physicist Jacob Bekenstein. Whats remarkable is that the correct boost factor requires the external field effect from the Milky Way galaxy, a unique prediction of MOND-type modified gravity. Thus, the wide binary data indicate not only the breakdown of Newtonian dynamics but also the manifestation of the external field effect of modified gravity.

On the results, Chae says, It seems impossible that a conspiracy or unknown systematic can cause these acceleration-dependent breakdowns of the standard gravity in agreement with AQUAL. I have examined all possible systematics as described in the rather long paper. The results are genuine. I foresee that the results will be confirmed and refined with better and larger data in the future. I have also released all my codes for the sake of transparency and to serve any interested researchers.

Unlike galactic rotation curves, where the observed boosted accelerations can theoretically be attributed to dark matter in the Newton-Einstein standard gravity, wide binary dynamics cannot be affected by it even if it existed. The standard gravity simply breaks down in the weak acceleration limit in accordance with the MOND framework.

The implications of wide binary dynamics are profound for astrophysics, theoretical physics, and cosmology. Anomalies in Mercurys orbits observed in the nineteenth century eventually led to Einsteins general relativity. Now anomalies in wide binaries demand a new theory extending general relativity to the low acceleration MOND limit.

Despite all the successes of Newtons gravity, general relativity is needed for relativistic gravitational phenomena such as black holes and gravitational waves. Likewise, despite all the successes of general relativity, a new theory is needed for MOND phenomena in the weak acceleration limit. The weak-acceleration catastrophe of gravity may have some similarity to the ultraviolet catastrophe of classical electrodynamics that led to quantum physics.

Wide binary anomalies are disastrous for standard gravity and cosmology that rely on dark matter and dark energy concepts. Since gravity follows MOND, a large amount of dark matter in galaxies (and even in the universe) is no longer needed. This is a significant surprise to Chae who, like typical scientists, believed in dark matter until a few years ago.

A new revolution in physics seems now underway. On the present results and the future prospects, Milgrom says, Chaes finding is a result of a very involved analysis of cutting-edge data, which, as far as I can judge, he has performed very meticulously and carefully. But for such a far-reaching finding and it is indeed very far-reaching we require confirmation by independent analyses, preferably with better future data. If this anomaly is confirmed as a breakdown of Newtonian dynamics, and especially if it indeed agrees with the most straightforward predictions of MOND, it will have enormous implications for astrophysics, cosmology, and for fundamental physics at large.

Xavier Hernandez, professor at UNAM in Mexico who first suggested wide binary tests of gravity a decade ago, says, It is exciting that the departure from Newtonian gravity that my group has claimed for some time has now been independently confirmed, and impressive that this departure has for the first time been correctly identified as accurately corresponding to a detailed MOND model. The unprecedented accuracy of the Gaia satellite, the large and meticulously selected sample Chae uses and his detailed analysis, make his results sufficiently robust to qualify as a discovery.

Pavel Kroupa, professor at Bonn University and at Charles University in Prague, has come to the same conclusions concerning the law of gravitation. He says, With this test on wide binaries as well as our tests on open star clusters nearby the Sun, the data now compellingly imply that gravitation is Milgromian rather than Newtonian. The implications for all of astrophysics are immense.

The finding was published in the 1 August 2023 issue of The Astrophysical Journal.

Reference: Breakdown of the NewtonEinstein Standard Gravity at Low Acceleration in Internal Dynamics of Wide Binary Stars by Kyu-Hyun Chae, 24 July 2023, The Astrophysical Journal. DOI: 10.3847/1538-4357/ace101

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Conclusive Evidence for Modified Gravity: Collapse of Newton's and ... - SciTechDaily

Physicists identified a mechanism behind oscillating superconductivity, called pair-density waves, through structures known as Van Hove singularities. This discovery offers a deeper understanding of unconventional superconductive states found in specific materials, including high-temperature superconductors.

Physicists have pinpointed a mechanism responsible for the creation of oscillating superconductivity, termed pair-density waves. The findings, which shed light on an atypical high-temperature superconductive state observed in specific materials like high-temperature superconductors, were published in Physical Review Letters.

We discovered that structures known as Van Hove singularities can produce modulating, oscillating states of superconductivity, says Luiz Santos, assistant professor of physics at Emory University and senior author of the study. Our work provides a new theoretical framework for understanding the emergence of this behavior, a phenomenon that is not well understood.

The first author of the study is Pedro Castro, an Emory physics graduate student. Co-authors include Daniel Shaffer, a postdoctoral fellow in the Santos group, and Yi-Ming Wu from Stanford University.

Santos is a theorist who specializes in condensed matter physics. He studies the interactions of quantum materials tiny things such as atoms, photons, and electrons that dont behave according to the laws of classical physics.

Superconductivity, or the ability of certain materials to conduct electricity without energy loss when cooled to a super-low temperature, is one example of intriguing quantum behavior. The phenomenon was discovered in 1911 when Dutch physicist Heike Kamerlingh Onnes showed that mercury lost its electrical resistance when cooled to 4 Kelvin or minus 371 degrees Fahrenheit. Thats about the temperature of Uranus, the coldest planet in the solar system.

It took scientists until 1957 to come up with an explanation for how and why superconductivity occurs. At normal temperatures, electrons roam more or less independently. They bump into other particles, causing them to shift speed and direction and dissipate energy. At low temperatures, however, electrons can organize into a new state of matter.

Luiz Santos, assistant professor of physics at Emory University, is the senior author of the study. Credit: Emory University

They form pairs that are bound together into a collective state that behaves like a single entity, Santos explains. You can think of them like soldiers in an army. If they are moving in isolation they are easier to deflect. But when they are marching together in lockstep its much harder to destabilize them. This collective state carries current in a robust way.

Superconductivity holds huge potential. In theory, it could allow for electric current to move through wires without heating them up or losing energy. These wires could then carry far more electricity, far more efficiently.

One of the holy grails of physics is room-temperature superconductivity that is practical enough for everyday-living applications, Santos says. That breakthrough could change the shape of civilization.

Many physicists and engineers are working on this frontline to revolutionize how electricity gets transferred.

Meanwhile, superconductivity has already found applications. Superconducting coils power electromagnets used in magnetic resonance imaging (MRI) machines for medical diagnostics. A handful of magnetic levitation trains are now operating in the world, built on superconducting magnets that are 10 times stronger than ordinary electromagnets. The magnets repel each other when the matching poles face each other, generating a magnetic field capable of levitating and propelling a train.

The Large Hadron Collider, a particle accelerator that scientists are using to research the fundamental structure of the universe, is another example of technology that runs through superconductivity.

Superconductivity continues to be discovered in more materials, including many that are superconductive at higher temperatures.

One focus of Santos research is how interactions between electrons can lead to forms of superconductivity that cannot be explained by the 1957 description of superconductivity. An example of this so-called exotic phenomenon is oscillating superconductivity, when the paired electrons dance in waves, changing amplitude.

In an unrelated project, Santos asked Castro to investigate specific properties of Van Hove singularities, structures where many electronic states become close in energy. Castros project revealed that the singularities appeared to have the right kind of physics to seed oscillating superconductivity.

That sparked Santos and his collaborators to delve deeper. They uncovered a mechanism that would allow these dancing-wave states of superconductivity to arise from Van Hove singularities.

As theoretical physicists, we want to be able to predict and classify behavior to understand how nature works, Santos says. Then we can start to ask questions with technological relevance.

Some high-temperature superconductors which function at temperatures about three times as cold as a household freezer have this dancing-wave behavior. The discovery of how this behavior can emerge from Van Hove singularities provides a foundation for experimentalists to explore the realm of possibilities it presents.

I doubt that Kamerlingh Onnes was thinking about levitation or particle accelerators when he discovered superconductivity, Santos says. But everything we learn about the world has potential applications.

Reference: Emergence of the Chern Supermetal and Pair-Density Wave through Higher-Order Van Hove Singularities in the Haldane-Hubbard Model by Pedro Castro, Daniel Shaffer, Yi-Ming Wu and Luiz H. Santos, 11 July 2023, Physical Review Letters. DOI: 10.1103/PhysRevLett.131.026601

The work was funded by the U.S. Department of Energys Office of Basic Energy Sciences.

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Physicists Open New Path to an Exotic Form of Superconductivity - SciTechDaily