Recently, a team of researchers from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences (CAS) consecutively removed the innermost atom and the outermost electron of a gold nanoparticle—without disturbing its overall structure. This precise manipulation allowed them to probe how the magnetic spin of the material influences its catalytic activity.
The work, led by Prof. Wu Zhikun in collaboration with Prof. Yang from the Institute of Process Engineering, CAS and Prof. Tang from Chongqing University, was published in Science Advances.
Gold nanoclusters—tiny particles composed of from a few to hundreds of gold atoms —are ideal models for studying how atomic structure affects material properties. But tuning the structure of such clusters atom by atom, especially when they’re relatively large and complex, has long been a major challenge.
A research team has successfully fine-tuned the Rabi oscillation of polaritons, quantum composite particles, by leveraging changes in electrical properties induced by crystal structure transformation. Published in Advanced Science, this study demonstrates that the properties of quantum particles can be controlled without the need for complex external devices, which is expected to greatly enhance the feasibility of practical quantum technology. The team was led by Professor Chang-Hee Cho from the Department of Physics and Chemistry at DGIST.
Quantum technology enables much faster and more precise information processing than conventional electronic devices and is gaining attention as a key driver of future industries, including quantum computing, communications, and sensors. At the core of this technology lies the ability to accurately generate and control quantum states. In particular, recent research has been actively exploring light-based quantum devices, with polaritons at the center of this field.
Polaritons are composite quasiparticles formed through the hybridization of photons and excitons—bound states arising from the motion of electrons. These quasiparticles travel at the speed of light while retaining the ability to interact with other particles, much like electrons.
Top quarks and antiquarks have been detected in heavy-ion collisions at the Large Hadron Collider, showing that all six quark flavors were present in the Universe’s first moments.
Quarks, the fundamental building blocks of matter, are usually confined within hadrons, such as protons and neutrons, by the strong force. But in the first moments after the big bang, quarks and gluons moved freely in an extremely hot, dense state of matter called a quark–gluon plasma (QGP) [1]. This “primordial soup” was the Universe’s first form of matter, existing for roughly 10 microseconds after the big bang, until the Universe cooled sufficiently for quarks and gluons to combine [2]. Scientists recreate and study these early-Universe conditions by smashing together ultrarelativistic heavy nuclei at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory in New York, the Large Hadron Collider (LHC) at CERN in Switzerland, and similar facilities.
For many years, physics studies focused on two main types of magnetism, namely ferromagnetism and antiferromagnetism. The first type entails the alignment of electron spins in the same direction, while the latter entails the alignment of electron spins in alternating, opposite directions.
Yet recent studies have discovered a new kind of magnetism, referred to as altermagnetism, which does not fit into either of the previously identified categories. Altermagnetism is characterized by the breaking of time-reversal symmetry (i.e., the symmetry of physical laws when time is reversed) and spin-split band structures, in materials that retain a zero net magnetization.
Researchers at the Chinese Academy of Sciences and other institutes in China recently uncovered a new material that exhibits altermagnetism at room temperature, namely KV2Se2O. Their findings, published in Nature Physics, highlight the promise of KV₂Se₂O both for the study of altermagnetism and for the development of spintronic devices.
For the better part of a century, the quantum objects known as quasiparticles have been all dressed up with nowhere to go. But that may change, now that a Yale-led team of physicists has shown it is possible to exert a greater level of control over at least one type of quasiparticle.
The discovery upends decades of fundamental science and may have wide applications for quantum-related research in the years ahead.
A quasiparticle is an “emergent” quantum object—a central, core particle surrounded by other particles that, together, demonstrate properties not found in each individual component. Quasiparticles have become the central conceptual picture by which scientists try to understand interacting quantum systems, including those that may be used in computing, sensors, and other devices.
Lacquers, paint, concrete—and even ketchup or orange juice: Suspensions are widespread in industry and everyday life. By a suspension, materials scientists mean a liquid in which tiny, insoluble solid particles are evenly distributed. If the concentration of particles in such a mixture is very high, phenomena can be observed that contradict our everyday understanding of a liquid. For example, these so-called non-Newtonian fluids suddenly become more viscous when a strong force acts upon them. For a brief moment, the liquid behaves like a solid.
This sudden thickening is caused by the particles present in the suspension. If the suspension is deformed, the particles have to rearrange themselves. From an energy perspective, it is more advantageous if they roll past each other whenever possible. It is only when this is no longer possible, e.g., because several particles become jammed, that they have to slide relative to each other. However, sliding requires much more force and thus the liquid feels macroscopically more viscous.
The interactions that occur on a microscopically small scale therefore affect the entire system and they determine how a suspension flows. To optimize the suspension and specifically influence its flow characteristics, scientists must therefore understand the magnitude of the frictional forces between the individual particles.
For centuries, humans have made use of glass in their art, tools, and technology. Despite the ubiquity of this material, however, many of its microscopic properties are not well understood, and it continues to defy conventional physical description.
Enter Koun Shirai of the University of Osaka. In an article published in Foundations, Shirai bridges conventional physical theory and the study of nonequilibrium materials to provide a robust description for the thermodynamics of glasses.
Most materials exist in an equilibrium state, meaning that the forces and torques on the material’s atoms are all balanced. Glasses, however, are a famous exception: they are amorphous solid materials whose atoms are always rearranging, albeit very slowly, toward an equilibrium state but do not exist in equilibrium.
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Panpsychism is the theory that consciousness is irreducible and exists fundamentally at the foundations of reality. Panpsychism forms include ‘micropsychism,’ where fundamental particles or fields are in some sense conscious, and ‘Cosmopsychism,’ where the entire universe is in some sense conscious. What are the arguments for and against Panpsychism like the ‘combination problem’?
Closer To Truth is now on BlueSky! Follow us for updates, new videos, musings, and more: https://bsky.app/profile/closertotrut… Kastrup is a Brazilian-born Dutch philosopher and computer scientist best known for his work in the field of consciousness studies, particularly his development of analytic idealism, a form of metaphysical idealism grounded in the analytic philosophical tradition. Make a tax-deductible donation of any amount to help us continue exploring the world’s deepest questions: https://closertotruth.com/donate/ Closer To Truth, hosted by Robert Lawrence Kuhn, presents the world’s greatest thinkers exploring humanity’s deepest questions. Discover fundamental issues of existence. Engage new and diverse ways of thinking. Appreciate intense debates. Share your own opinions. Seek your own answers.
Bernardo Kastrup is a Brazilian-born Dutch philosopher and computer scientist best known for his work in the field of consciousness studies, particularly his development of analytic idealism, a form of metaphysical idealism grounded in the analytic philosophical tradition.
Make a tax-deductible donation of any amount to help us continue exploring the world’s deepest questions: https://closertotruth.com/donate/
Closer To Truth, hosted by Robert Lawrence Kuhn, presents the world’s greatest thinkers exploring humanity’s deepest questions. Discover fundamental issues of existence. Engage new and diverse ways of thinking. Appreciate intense debates. Share your own opinions. Seek your own answers.
