Where do protons and neutrons get their mass and spin? Surprisingly, we don’t know. A new facility promises to peek inside these particles to find answers.
Researchers at Technische Universität Darmstadt have recently demonstrated the defect-free assembly of versatile target patterns of up to 111 single-atom quantum systems. Their findings, outlined in a paper published in Physical Review Letters, could drive assembled-atom architectures beyond the threshold of quantum advantage, paving the way for new breakthroughs in quantum science and technology.
“Our research is driven by the observation that physical sciences are right in the middle of a paradigm shift in which the application of quantum physics, i.e. quantum technologies, are becoming the leading technologies in the near future,” Gerhard Birkl, one of the researchers who carried out the study, told Phys.org. “A vast list of applications are already foreseeable but I am convinced that of most applications we are not even aware of.”
The next step for the field of quantum science and technology is the development of experimental platforms that offer extensive scalability, multisite quantum correlations and efficient quantum error correction. Over the past century or so, researchers have carried out a substantial amount of work on single quantum systems, laying the foundations for current developments. Atomic quantum systems have played a key role in these studies, particularly neutral atoms trapped by light, as they provide well-isolated quantum systems with favorable scaling.
The quotation marks had the force of tradition—and the tradition of force—behind them.
When Nebraska’s Herman Batelaan and colleagues recently submitted a research paper that makes the case for the existence of a non-Newtonian, quantum force, the journal asked that they place “force” firmly within quotes. The team understood and agreed to the request.
After all, the word has long belonged to classical Newtonian physics: equal-and-opposite reactions, electromagnetism, gravity and other laws that explain the apple-dropping, head-bonking phenomena of everyday experience.
Continue reading “Study points to non-Newtonian force affecting particles’ flight” »
A pair of researchers, one at the Massachusetts Institute of Technology (MIT) and another at California Institute of Technology (Caltech) and the University of Tokyo, have recently investigated a set of old conjectures about symmetries in quantum gravity. The specific conjectures of focus: Quantum gravity does not allow for global symmetries; For gauge symmetry, all possible charges must be realized; Internal gauge groups must be compact. Their paper, published in Physical Review Letters, shows that these old assumptions hold within the anti-de Sitter/conformal field theory (AdS-CFT) correspondence.
“Historically, the concept of symmetry has played important roles in physics, both in identifying and formulating fundamental laws of nature, and in using these laws to understand and predict natural phenomena such as dynamics and phases of matters,” Hirosi Ooguri, one of the researchers who carried out the study, told Phys.org. “However, there has been theoretical evidence to suggest that, once we combine gravity and quantum mechanics (the two fundamental ideas in modern physics), all global symmetries are gone.”
In physics, symmetries can be of two kinds: gauge and global. For several decades, researchers have proposed the idea that global symmetries should not be possible in quantum gravity, as the unified theory of gravity and quantum mechanics would not allow for any symmetry. This is a profound claim with important consequences. For instance, it predicts that a proton would not be stable against decaying into other particles.
Continue reading “Researchers demonstrate constraints on symmetries from holography” »
Astronomers have carried out a multiwavelength investigation of a pulsar wind nebula (PWN), designated DA 495, to unveil its mysterious physical nature. Results of the study, based on observations using HAWC and VERITAS ground-based observatories as well as NASA’s NuSTAR spacecraft, are presented in a paper published May 17 on arXiv.org.
Pulsar wind nebulae (PWNe) are nebulae powered by the wind of a pulsar. Pulsar wind is composed of charged particles; when it collides with the pulsar’s surroundings, in particular with the slowly expanding supernova ejecta, it develops a PWN.
Particles in PWNe lose their energy to radiation and become less energetic with distance from the central pulsar. Multiwavelength studies of these objects, including X-ray observations, especially using spatially-integrated spectra in the X-ray band, have the potential of uncovering important information about particle flow in these nebulae. This could unveil important insights into the nature of PWNe in general.
Continue reading “Astronomers investigate pulsar wind nebula DA 495” »
Scientist have just discovered that, at an atomic level, these elements have both liquid and solid states, giving context to what may be hidden in the cores of celestial bodies.
A New State of Water Reveals a Hidden Ocean in Earth’s Mantle — https://youtu.be/pgm4z8vJVVk
Continue reading “This New State of Matter Is a Liquid and a Solid at the Same Time!” »
Some research topics, says conventional wisdom, a physics PhD student shouldn’t touch with an iron-tipped medieval lance: sinkholes in the foundations of quantum theory. Problems so hard, you’d have a snowball’s chance of achieving progress. Problems so obscure, you’d have a snowball’s chance of convincing anyone to care about progress. Whether quantum physics could influence cognition much.
Quantum physics influences cognition insofar as (i) quantum physics prevents atoms from imploding and (ii) implosion inhabits atoms from contributing to cognition. But most physicists believe that useful entanglement can’t survive in brains. Entanglement consists of correlations shareable by quantum systems and stronger than any achievable by classical systems. Useful entanglement dies quickly in hot, wet, random environments.
Brains form such environments. Imagine injecting entangled molecules A and B into someone’s brain. Water, ions, and other particles would bombard the molecules. The higher the temperature, the heavier the bombardment. The bombardiers would entangle with the molecules via electric and magnetic fields. Each molecule can share only so much entanglement. The more A entangled with the environment, the less A could remain entangled with B. A would come to share a tiny amount of entanglement with each of many particles. Such tiny amounts couldn’t accomplish much. So quantum physics seems unlikely to affect cognition significantly.
Continue reading “Quantum information in quantum cognition” »
