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Archive for the ‘particle physics’ category: Page 324

Jul 14, 2021

Nickel isotopes link Siberian Traps aerosol particles to the end-Permian mass extinction

Posted by in categories: existential risks, particle physics

The Sverdrup Basin was a Carboniferous to Paleogene depocenter that accumulated over 12 km of sediment from Carboniferous to Paleogene time18 (Fig. 1). From Late Carboniferous to Early Triassic time, the Sverdrup Basin was along the NW margin of Pangea at palaeolatitudes of 35–40°N (ref. 19) (Fig. 1). Until the EPME, the basin was characterised by a central deep basinal area of fine-grained clastic deposition surrounded by a shallow shelf dominated by biogenic carbonate that transitioned in the late Permian to chert formed by shallow water siliceous sponges19. After the EPME, the Sverdrup basin was dominated by clastic-dominated sedimentation18. In this study, we examined the distal deep-water Buchanan Lake section which preserves outstanding Boreal records of the EPME, followed by the biotic recovery in the Early Triassic5. The Buchanan Lake section consists mostly of black shale of the Late Permian Black Stripe Formation and overlying Early Triassic Blind Fiord Formation that preserves characteristic post-extinction fauna20 (Fig. 2).

During the last decade, the Buchanan Lake section has been extensively examined, and the carbon isotope chemostratigraphy, elemental compositions of the shale, and oceanic palaeo-redox changes have been well constrained5, 11, 19, 20, 21, 22, 23, 24, 25, 26 (Fig. 2). The EPME in the Sverdrup Basin is marked by eradication of silica and carbonate producers along with the onset of a significant negative δ13 Corg shift that has been correlated globally with the dated Global Stratotype Section and Point (GSSP) for the Permian-Triassic boundary at Meishan, China, at ~251.9 Ma (refs. 3, 4, 20, 27, 28) (Fig. 2). The palaeo-redox conditions during the deposition of the Late Permian Black Stripe Formation and Early Triassic Blind Fiord Formation evolved from an oxic water column with a strong redoxcline in the sediments to anoxic and then to sulphidic bottom water conditions (Fig. 2).

Jul 13, 2021

Plasma Particle Accelerators Could Find New Physics

Posted by in category: particle physics

The next big collider will likely rely on novel technology.

Jul 13, 2021

Seeing with radio waves

Posted by in categories: computing, particle physics, quantum physics

Scientists from the Division of Physics at the University of Tsukuba used the quantum effect called ‘spin-locking’ to significantly enhance the resolution when performing radio-frequency imaging of nitrogen-vacancy defects in diamond. This work may lead to faster and more accurate material analysis, as well as a path towards practical quantum computers.

Nitrogen-vacancy (NV) centers have long been studied for their potential use in quantum computers. A NV center is a type of defect in the lattice of a diamond, in which two adjacent carbon atoms have been replaced with a nitrogen atom and a void. This leaves an unpaired electron, which can be detected using radio-frequency waves, because its probability of emitting a photon depends on its . However, the of radio wave detection using conventional radio-frequency techniques has remained less than optimal.

Now, researchers at the University of Tsukuba have pushed the resolution to its limit by employing a technique called ‘spin-locking’. Microwave pulses are used to put the electron’s spin in a quantum superposition of up and down simultaneously. Then, a driving electromagnetic field causes the direction of the spin to precess around, like a wobbling top. The end result is an electron spin that is shielded from random noise but strongly coupled to the detection equipment. “Spin-locking ensures high accuracy and sensitivity of the electromagnetic field imaging,” first author Professor Shintaro Nomura explains. Due to the high density of NV centers in the diamond samples used, the collective signal they produced could be easily picked up with this method. This permitted the sensing of collections of NV centers at the micrometer scale.

Jul 12, 2021

Higher-Energy Composite Fermion Levels in the Fractional Quantum Hall Effect

Posted by in categories: particle physics, quantum physics

😀 2011


Trevor D. Rhone, Dwipesh Majumder, Brian S. Dennis, Cyrus Hirjibehedin, Irene Dujovne, Javier G. Groshaus, Yann Gallais, Jainendra K. Jain, Sudhansu S. Mandal, Aron Pinczuk, Loren Pfeiffer, and Ken West. 2011. “Higher-Energy Composite Fermion Levels in the Fractional Quantum Hall Effect.” Phys. Rev. Lett., 106, Pp. 096803.

Jul 12, 2021

A Massless Particle Which Could Revolutionize Electronics

Posted by in categories: computing, information science, particle physics, quantum physics

In 2015, after 85 years of searching, researchers confirmed the existence of a massless particle called the Weyl fermion. With the unique ability to behave as both matter and anti-matter inside a crystal, this quasiparticle is like an electron with no mass. The story begun in 1928 when Dirac proposed an equation for the foundational unification of quantum mechanics and special relativity in describing the nature of the electron. This new equation suggested three distinct forms of relativistic particles: the Dirac, the Majorana, and the Weyl fermions. And recently, an analog of Weyl fermions has been discovered in certain electronic materials exhibiting a strong spin orbit coupling and topological behavior. Just as Dirac fermions emerge as signatures of topological insulators, in certain types of semimetals, electrons can behave like Weyl fermions.

These Weyl fermions are what can be called quasiparticles, which means they can only exist in a solid such as a crystal, and not as standalone particles. However, as complex as quasiparticles sound, their behavior is actually much simpler than that of fundamental particles, because their properties allow them to shrug off the same forces that knock their counterparts around. This discovery of Weyl fermions is huge, not just because there is finally a proof that these elusive particles exist, but because it paves the way for far more efficient electronics, and new types of quantum computing. Weyl fermions could be used to solve the traffic jams with electrons in electronics. In fact, Weyl electrons can carry charges at least 1000 times faster than electrons in ordinary semiconductors, and twice as fast as inside graphene. This could lead to a whole new type of electronics called ‘Weyltronics’.

Jul 12, 2021

For The First Time, Scientists Have Connected a Superconductor to a Semiconductor

Posted by in categories: mobile phones, particle physics, quantum physics

Scientists have succeeded in combining two exciting material types together for the very first time: an ultrathin semiconductor just a single atom thick; and a superconductor, capable of conducting electricity with zero resistance.

Both these materials have unusual and fascinating properties, and by putting them together through a delicate lab fabrication process, the team behind the research is hoping to open up all kinds of new applications in classical and quantum physics.

Semiconductors are key to the electrical gadgets that dominate our lives, from TVs to phones. What makes them so useful as opposed to regular metals is their electrical conductivity can be adjusted by applying a voltage to them (among other methods), making it easy to switch a current flow on and off.

Jul 11, 2021

Researchers Discover Orbital Patterns of Trans-Neptunian Objects Vary Based on Their Color

Posted by in categories: chemistry, evolution, particle physics, space

Data collected can be used to provide new insights into the evolution of the Kuiper Belt, and the larger solar system.

Trans-Neptunian Objects (TNOs), small objects that orbit the sun beyond Neptune, are fossils from the early days of the solar system which can tell us a lot about its formation and evolution.

A new study led by Mohamad Ali-Dib, a research scientist at the NYU Abu Dhabi Center for Astro, Particle, and Planetary Physics, reports the significant discovery that two groups of TNOs with different surface colors also have very different orbital patterns. This new information can be compared to models of the solar system to provide fresh insights into its early chemistry. Additionally, this discovery paves the way for further understanding of the formation of the Kuiper Belt itself, an area beyond Neptune comprised of icy objects, that is also the source of some comets.

Jul 11, 2021

Recycling Lost Energy: Quantum Laser Turns Energy Loss Into Gain?

Posted by in categories: particle physics, quantum physics, sustainability

A new laser that generates quantum particles can recycle lost energy for highly efficient, low threshold laser applications.

Scientists at KAIST have fabricated a laser system that generates highly interactive quantum particles at room temperature. Their findings, published in the journal Nature Photonics, could lead to a single microcavity laser system that requires lower threshold energy as its energy loss increases.

The system, developed by KAIST physicist Yong-Hoon Cho and colleagues, involves shining light through a single hexagonal-shaped microcavity treated with a loss-modulated silicon nitride substrate. The system design leads to the generation of a polariton laser at room temperature, which is exciting because this usually requires cryogenic temperatures.

Jul 11, 2021

Muon g-2 Experiment Results – Profound Implications for the History of the Universe

Posted by in categories: particle physics, space

Experiment opens up field for new physics, say Fermilab, UChicago scientists.

The news that muons have a little extra wiggle in their step sent word buzzing around the world this spring.

Continue reading “Muon g-2 Experiment Results – Profound Implications for the History of the Universe” »

Jul 11, 2021

Giant Quantum Tornados in Hybrid Light-Matter System Reveal Complex Physical Phenomena

Posted by in categories: climatology, particle physics, quantum physics

Researchers from Skoltech and their colleagues from the UK have managed to create a stable giant vortex in interacting polariton condensates, addressing a known challenge in quantized fluid dynamics. The findings open possibilities in creating uniquely structured coherent light sources and exploring many-body physics under unique extreme conditions. The paper was published in the journal Nature Communications.

In fluid dynamics, a vortex is a region where a fluid revolves around a point (2D) or a line (3D); you’ve clearly seen one in your sink or may have felt one in the form of turbulence while flying. The quantum world also has vortices: the flow of a quantum fluid can create a zone where the particles revolve persistently around some point. The prototypical signature of such quantum vortices is their singular phase at the core of the vortex.

Skoltech Professors Natalia Berloff and Pavlos Lagoudakis and colleagues studied vortices created by polaritons – odd hybrid quantum particles that are half-light (photon) and half-matter (electrons) – forming a quantum fluid under the right conditions. They were looking for a way to create vortices in these polariton fluids with high values of angular momentum (i.e., getting them to rotate fast). These vortices, also known as giant vortices, are generally very hard to obtain as they tend to break apart into many smaller vortices with low angular momentum in other systems.