Quantum calculations amount to sophisticated estimates. But in 1931, Hans Bethe intuited precisely how a chain of particles would behave — an insight that had far-reaching consequences.
Category: particle physics – Page 62
Accidental Breakthrough As Supercooled Wires Detect Near-Light-Speed Protons
Researchers have discovered that superconducting nanowire photon.
A photon is a particle of light. It is the basic unit of light and other electromagnetic radiation, and is responsible for the electromagnetic force, one of the four fundamental forces of nature. Photons have no mass, but they do have energy and momentum. They travel at the speed of light in a vacuum, and can have different wavelengths, which correspond to different colors of light. Photons can also have different energies, which correspond to different frequencies of light.
Simulations reveal Anderson transition for light in 3D disordered systems
The Anderson transition is a phase transition that occurs in disordered systems, which entails a shift from a diffusive state (i.e., in which waves or particles are spread out) to a localized state, in which they are trapped in specific regions. This state was first studied by physicist Philip W. Anderson, who examined the arrangement of electrons in disordered solids, yet it was later found to also apply to the propagation of light and other waves.
Researchers at Missouri University of Science & Technology, Yale University, and Grenoble Alpes University in France recently set out to further explore the Anderson transition for light (i.e., electromagnetic waves) in 3D disordered systems.
Their paper, published in Physical Review Letters, outlines the simulation of light wave transport in an arrangement of perfect-electric-conducting (PEC) spheres, materials that reflect electromagnetic waves.
Scientists achieve electrical manipulation of spin filling sequence in bilayer graphene quantum dots
A research team from the University of Science and Technology of China has demonstrated the ability to electrically manipulate the spin filling sequence in a bilayer graphene (BLG) quantum dot (QD). This achievement, published in Physical Review Letters, showcases the potential to control the spin degree of freedom in BLG, a material with promising applications in quantum computing and advanced electronics.
BLG has drawn extensive attention in recent years due to its unique properties. When an out-of-plane electric field is applied, it can generate a tunable band gap. Moreover, the trigonal warping effect, caused by the skew interlayer coupling, gives rise to additional minivalley degeneracy, greatly influencing the behavior of charge carriers. Quantum dot devices, which can precisely control the number of charge carriers, have become a crucial tool for studying these phenomena at the single-particle level.
The research team delved into the intricate dynamics of electron shell structures within bilayer graphene quantum dot, focusing on how these structures can be manipulated through the trigonal warping effect, a unique feature of bilayer graphene. They employed a highly tunable quantum dot device, which provided the means to control the electron filling sequence. They began by applying a small perpendicular electric field, observing that the s-shell filled with four electrons, two with spin-up and two with spin-down, each from opposite valleys.
3.5 Kilometers Underwater, Scientists Found a Staggeringly Energetic Particle From Outer Space
Three and a half kilometers beneath the Mediterranean Sea, around 80km off the coast of Sicily, lies half of a very unusual telescope called KM3NeT.
The enormous device is still under construction, but today the telescope’s scientific team announced they have already detected a particle from outer space with a staggering amount of energy.
In fact, as the team report in Nature, they found the most energetic neutrino anyone has ever seen—and it represents a tremendous leap forward in exploring the uncharted waters of the extreme universe.
Scientists Just Unlocked a New Way to Supercharge Wireless Speeds With Graphene
Researchers have made a breakthrough in THz frequency conversion using graphene.
Graphene is an allotrope of carbon in the form of a single layer of atoms in a two-dimensional hexagonal lattice in which one atom forms each vertex. It is the basic structural element of other allotropes of carbon, including graphite, charcoal, carbon nanotubes, and fullerenes. In proportion to its thickness, it is about 100 times stronger than the strongest steel.
The Hidden Currents of Reality: An Overview of Infodynamics
In the grand sweep of scientific history, revolutions in thought are often born from a simple yet unsettling realization: that the fundamental nature of reality is not what we once assumed it to be. In the 20th century, physics was shaken by the twin cataclysms of relativity and quantum mechanics, revealing that space and time themselves were malleable, that particles could exist in superpositions, and that observation played a fundamental role in shaping what we call reality.
Electron correlations dominate processes in sub-nanometer particles
Light-sensitive nanoparticles promise a wide range of applications, for example in the field of sensor technology or energy generation. However, these require knowledge and control of the processes taking place within them. Plasmons, collective electron movements in the nanoparticle which transport energy, are essential in the behaviour of such nanoparticles.
Time-resolved experiments in the attosecond range reveal now that the importance of electronic correlations in these plasmons increases when the size of a system decreases to scales of less than one nanometre.
The study, published in the journal Science Advances (“Correlation-driven attosecond photoemission delay in the plasmonic excitation of C 60 fullerene”), was led by the University of Hamburg and DESY as part of a collaboration with Stanford, SLAC National Accelerator Laboratory, Ludwig-Maximilians-Universität München (LMU), Northwest Missouri State University, Politecnico di Milano and the Max Planck Institute for the Structure and Dynamics of Matter (MPSD).