Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics – Page 140

Engineers achieve quantum teleportation over active internet cables

Engineers at Northwestern University have demonstrated quantum teleportation over a fiber optic cable already carrying Internet traffic. This feat, published in the journal Optica, opens up new possibilities for combining quantum communication with existing Internet infrastructure. It also has major implications for the field of advanced sensing technologies and quantum computing applications.

Quantum teleportation, a process that harnesses the power of quantum entanglement, enables an ultra-fast and secure method of information sharing between distant network users. Unlike traditional communication methods, quantum teleportation does not require the physical transmission of particles. Instead, it relies on entangled particles exchanging information over great distances.

Nobody thought it would be possible to achieve this, according to Professor Prem Kumar, who led the study. “Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure. Basically, it opens the door to pushing quantum communications to the next level.”

Black holes may not exist as we know them, but fuzzballs might

String theory proposes that all particles and forces are made of tiny, vibrating strings, which form the fundamental building blocks of the universe. This framework offers a potential solution to the long-standing paradoxes surrounding black holes, such as their singularities—infinitely tiny points where the laws of physics break down—and the Hawking radiation paradox, which questions the fate of information falling into black holes.

Fuzzballs replace the singularity with an ultra-compressed sphere of strings, likened to a neutron star’s structure but composed of subatomic strings instead of particles. While the theory remains incomplete, its implications are significant, offering an alternative explanation for phenomena previously attributed to black holes.

To differentiate between black holes and fuzzballs, researchers are turning to gravitational waves—ripples in spacetime caused by cosmic collisions. When black holes merge, they emit specific gravitational wave signatures that have so far aligned perfectly with Einstein’s general relativity. However, fuzzballs might produce subtle deviations from these patterns, providing a way to confirm their existence.

CERN’s Large Hadron Collider finds the heaviest antimatter particle yet

Scientists from the ALICE (A Large Ion Collider Experiment) at CERN’s Large Hadron Collider reported evidence of a new antimatter particle called antihyperhelium-4, essentially the “evil twin” of another weird particle called hyperhelium-4. This incredibly exotic form of matter contains two antiprotons, an antineutron, and an unstable particle called an antilambda comprised of subatomic quarks.

Can Entangled Particles Communicate Faster than Light?

Entanglement is perhaps one of the most confusing aspects of quantum mechanics. On its surface, entanglement allows particles to communicate over vast distances instantly, apparently violating the speed of light. But while entangled particles are connected, they don’t necessarily share information between them.

In quantum mechanics, a particle isn’t really a particle. Instead of being a hard, solid, precise point, a particle is really a cloud of fuzzy probabilities, with those probabilities describing where we might find the particle when we go to actually look for it. But until we actually perform a measurement, we can’t exactly know everything we’d like to know about the particle.

These fuzzy probabilities are known as quantum states. In certain circumstances, we can connect two particles in a quantum way, so that a single mathematical equation describes both sets of probabilities simultaneously. When this happens, we say that the particles are entangled.

Ask Ethan: Do gravitons need to exist?

Which brings us to the big question: what about gravity?

This is something where we can’t be certain, as gravitation remains the only known force for which we don’t have a full quantum description. Instead, we have Einstein’s general relativity as our theory of gravity, which relies on a purely classical (i.e., non-quantum) formalism for describing it. According to Einstein, spacetime behaves as a four-dimensional fabric, and it’s the curvature and evolution of that fabric that determines how matter-and-energy move through it. Similarly it’s the presence and distribution of matter-and-energy that determine the curvature and evolution of spacetime itself: the two notions are linked together in an inextricable way.

Now, over on the quantum side, our other fundamental forces and interactions have both a quantum description for particles and a quantum description for the fields themselves. All calculations performed within all quantum field theories are calculated within spacetime, and while most of the calculations we perform are undertaken with the assumption that the underlying background of spacetime is flat and uncurved, we can also insert more complex spacetime backgrounds where necessary. It was such a calculation, for example, that led Stephen Hawking to predict the emission of the radiation that bears his name from black holes: Hawking radiation. Combining quantum field theory (in that case, for electromagnetism) with the background of curved spacetime inevitably leads to such a prediction.

Active particles reorganize 3D gels into denser porous structures, study shows

Colloidal gels are complex systems made up of microscopic particles dispersed in a liquid, ultimately producing a semi-solid network. These materials have unique and advantageous properties that can be tuned using external forces, which have been the focus of various physics studies.

Researchers at University of Copenhagen in Denmark and the UGC-DAE Consortium for Scientific Research in India recently ran simulations and performed analyses aimed at understanding how the injection of active particles, such as swimming bacteria, would influence colloidal gels.

Their paper, published in Physical Review Letters, shows that active particles can influence the structure of 3D colloidal gels, kneading them into porous and denser structures.

Mapping Spin Waves with a Strobe Light

A method for imaging spin waves in magnetic materials uses flash-like intensity variations in a laser beam to capture the wave motion at specific moments in time.

The magnetic moments, or spins, in certain materials can twirl in a coordinated wave pattern that might one day be used to transmit information in so-called spintronic devices. Researchers have developed a new way to image these spin waves using an infrared laser that essentially flashes on and off at a frequency that matches that of the spin waves [1]. Unlike other spin-wave probes, this strobe method can directly capture phase information that is relevant to certain applications, such as hybrid devices that combine spin waves with other types of waves.

A spin wave can be triggered in a magnetic material when some perturbation causes a spin to oscillate, which can then generate a wave of oscillations that ripple through neighboring spins. Spin waves have several properties that make them good candidates for information carriers. For one, they have relatively small wavelengths—a few hundred nanometers at a frequency of 1 GHz, whereas a 1-GHz photon has a wavelength of about 30 cm. This compactness could conceivably allow researchers to build spintronic components, such as waveguides and logic gates, at the nanoscale. Another advantage of these waves is that the spins remain in place, and only their orientation changes. So the heat losses that affect the moving charges in traditional electronics don’t exist.

/* */