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Archive for the ‘particle physics’ category: Page 358

May 13, 2020

Teleportation and traversible wormholes are all real

Posted by in categories: cosmology, particle physics, quantum physics, time travel

Circa 2017


Einstein-Rosen or “ER” bridges, are equivalent to entangled quantum particles, also known as Einstein-Podolsky-Rosen or “EPR” pairs. The quantum connection between wormholes prevents their collapse without involving exotic matter.

The quantum-teleportation format precludes using these traversable wormholes as time machines. Anything that goes through the wormhole has to wait for Alice’s message to travel to Bob in the outside universe before it can exit Bob’s black hole, so the wormhole doesn’t offer any superluminal boost that could be exploited for time travel.

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May 12, 2020

Quantum brakes in molecules

Posted by in categories: particle physics, quantum physics

Physicists have measured the flight times of electrons emitted from a specific atom in a molecule upon excitation with laser light. This has enabled them to measure the influence of the molecule itself on the kinetics of emission.

Photoemission—the release of electrons in response to excitation by light—is one of the most fundamental processes in the microcosm. The kinetic energy of the emitted electron is characteristic for the atom concerned, and depends on the wavelength of the light employed. But how long does the process take? And does it always take the same amount of time, irrespective of whether the electron is emitted from an individual atom or from an atom that is part of a molecule? An international team of researchers led by laser physicists in the Laboratory for Attosecond Physics (LAP) at LMU Munich and the Max Planck Institute of Quantum Optics (MPQ) in Garching has now probed the influence of the molecule on photoemission time.

The theoretical description of photoemission in 1905 by Albert Einstein marked a breakthrough in , and the details of the process are of continuing interest in the world of science and beyond. How the motions of an elementary quantum particle such as the electron are affected within a molecular environment has a significant bearing on our understanding of the process of photoemission and the forces that hold molecules together.

May 12, 2020

‘Milestone’ Evidence for Anyons, a Third Kingdom of Particles

Posted by in category: particle physics

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Anyons don’t fit into either of the two known particle kingdoms. To find them, physicists had to erase the third dimension.

May 12, 2020

“Quantum radar” uses entangled photons to detect objects

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

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The weird world of quantum physics is being harnessed for some fascinating use cases. In the latest example, physicists have developed and demonstrated a “quantum radar” prototype that uses the quantum entanglement phenomenon to detect objects, a system which could eventually outperform conventional radar in some circumstances.

Quantum entanglement describes the bizarre state where two particles can become linked so tightly that they seem to communicate instantly, no matter how far apart they are. Measuring the state of one particle will instantly change the state of the other, hypothetically even if it’s on the other side of the universe. That implies that the information is moving faster than the speed of light, which is thought to be impossible – and yet, it’s clearly and measurably happening. The phenomenon even unnerved Einstein himself, who famously described it as “spooky action at a distance.”

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May 11, 2020

Electromagnetic water cloak eliminates drag and wake

Posted by in categories: chemistry, particle physics

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object’s wake, greatly reducing its drag while simultaneously helping it avoid detection.

The idea originated at Duke University in 2011 when researchers outlined the general concept. By matching the acceleration of the surrounding water to an ’s movement, it would theoretically be possible to greatly increase its propulsion efficiency while leaving the surrounding sea undisturbed. The theory was an extension of the group’s pioneering work in metamaterials, where a material’s structure, rather than its chemistry, creates desired properties.

Six years later, Yaroslav Urzhumov, adjunct assistant professor of electrical and computer engineering at Duke, has updated the theory by detailing a potential approach. But rather than using a complex system of very small pumps as originally speculated, Urzhumov is turning to electromagnetic fields and the dense concentration of charged particles found in saltwater.

May 11, 2020

New Recipe for Single-Atom Transistors May Enable Quantum Computers With Unparalleled Memory and Processing Power

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

Linking multiple copies of these devices may lay the foundation for quantum computing.

Once unimaginable, transistors consisting only of several- atom clusters or even single atoms promise to become the building blocks of a new generation of computers with unparalleled memory and processing power. But to realize the full potential of these tiny transistors — miniature electrical on-off switches — researchers must find a way to make many copies of these notoriously difficult-to-fabricate components.

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May 11, 2020

Observations unveil the properties of neutrino-emitting blazar’s jet

Posted by in categories: cosmology, particle physics

Using the Very Long Baseline Interferometry (VLBI) technique, astronomers have probed the parsec-scale jet of a neutrino-emitting blazar known as TXS 0506+056. Results of the new study, presented May 1 on arXiv.org, shed more light on the properties of this jet, which could improve the understanding of very-high energy (VHE) neutrinos.

Blazars, classified as members of a larger group of active galaxies that host (AGN), are powerful sources of emission across the from radio to very gamma frequencies. Their characteristic features are pointed almost exactly toward the Earth.

In general, blazars are perceived by astronomers as high-energy engines serving as natural laboratories to study , relativistic plasma processes, magnetic field dynamics and black hole physics. Therefore, high-resolution observations of blazars and their jets in different wavelengths could be essential for improving the understanding of these phenomena.

May 8, 2020

Simple method for measuring the state of lithium-ion batteries

Posted by in categories: computing, mobile phones, particle physics, sustainability, transportation

Rechargeable batteries are at the heart of many new technologies involving, for example, the increased use of renewable energies. More specifically, they are employed to power electric vehicles, cell phones, and laptops. Scientists at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM) in Germany have now presented a non-contact method for detecting the state of charge and any defects in lithium-ion batteries. For this purpose, atomic magnetometers are used to measure the magnetic field around battery cells. Professor Dmitry Budker and his team usually use atomic magnetometry to explore fundamental questions of physics, such as the search for new particles. Magnetometry is the term used to describe the measurement of magnetic fields. One simple example of its application is the compass, which the Earth’s magnetic field causes to point north.

Non-contact quality assurance of batteries using atomic magnetometers

The demand for high-capacity is growing and so is the need for a form of sensitive, accurate diagnostic technology for determining the state of a battery cell. The success of many new developments will depend on whether batteries can be produced that can deliver sufficient capacity and a long effective life span. “Undertaking the quality assurance of rechargeable batteries is a significant challenge. Non-contact methods can potentially provide fresh stimulus for improvement in batteries,” said Dr. Arne Wickenbrock, a member of Professor Dmitry Budker’s work group at the JGU Institute of Physics and the Helmholtz Institute Mainz. The group has achieved a breakthrough by using atomic magnetometers to take measurements. The idea came about during a teleconference between Budker and his colleague Professor Alexej Jerschow of New York University. They developed a concept and, with close cooperation between the two groups, carried out the related experiments in Mainz.

May 8, 2020

Finite-temperature violation of the anomalous transverse Wiedemann-Franz law

Posted by in category: particle physics

According to the Wiedemann-Franz (WF) law, the electrical conductivity of a metal is linked to its thermal counterpart, provided that the heat carried by the phonons is negligible and the electrons do not suffer inelastic scattering. In a type II Weyl semimetal also known as a fourth fermion, the thermal dependence of the ratio between electrical and thermal conductivity highlights deviations from the Wiedemann-Franz law. Physicists have tested the WF law in numerous solids but intend to understand the extent of its relevance during anomalous transverse transport and investigate the topological nature of the wave function. In a new report, Liangcai Xu and an international research team in condensed matter physics in China, France, Israel and Germany, presented a study of the anomalous transverse response in a noncollinear antiferromagnetic Weyl semimetal, Mn3Ge. They varied the experimental conditions from room temperature down to sub-Kelvin temperature and observed finite-temperature violation of the WF correlation. They credited the outcome to a mismatch between the thermal and electrical summations of the Berry curvature (a geometric phase acquired within the course of a cycle) and not due to inelastic scattering. The team backed their interpretation with theoretical calculations to reveal a competition between the temperature and Berry curvature distribution. The work is now published on Science Advances.

The Berry curvature of electrons can result in the anomalous Hall effect (AHE) if the host solid lacks time-reversal symmetry (conservation of entropy). While the thermoelectric and thermal counterparts of the anomalous Hall effect are explored less frequently, they too arise from the same fictitious magnetic fields. It remains to be determined how the magnitudes of such anomalous off-diagonal coefficients correlate with each other and if the established correlations between ordinary transport coefficients continue to hold. It is currently laborious to form a semiclassical formula of the anomalous Hall effect (AHE), thereby making any intuitive picture of producing a transverse electric field even more challenging. In this work, the research team presented a study of a magnetic solid, focused on the relation between anomalous electrical and thermal Hall conductivities. Xu et al.

May 8, 2020

Successfully measuring infinitesimal change in mass of individual atoms for the first time

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

A new door to the quantum world has been opened: When an atom absorbs or releases energy via the quantum leap of an electron, it becomes heavier or lighter. This can be explained by Einstein’s theory of relativity (E = mc2). However, the effect is minuscule for a single atom. Nevertheless, the team of Klaus Blaum and Sergey Eliseev at the Max Planck Institute for Nuclear Physics has successfully measured this infinitesimal change in the mass of individual atoms for the first time. In order to achieve this, they used the ultra-precise Pentatrap atomic balance at the Institute in Heidelberg. The team discovered a previously unobserved quantum state in rhenium, which could be interesting for future atomic clocks. Above all, this extremely sensitive atomic balance enables a better understanding of the complex quantum world of heavy atoms.

Astonishing, but true: If you wind a mechanical watch, it becomes heavier. The same thing happens when you charge your smartphone. This can be explained by the equivalence of energy (E) and mass (m), which Einstein expressed in the most famous formula in physics: E = mc2 (c: speed of light in vacuum). However, this effect is so small that it completely eludes our everyday experience. A conventional balance would not be able to detect it.

But at the Max Planck Institute for Nuclear Physics in Heidelberg, there is a balance that can: Pentatrap. It can measure the minuscule change in mass of a single atom when an electron absorbs or releases energy via a quantum jump, thus opening a for precision physics. Such quantum jumps in the electron shells of atoms shape our world—whether in life-giving photosynthesis and general chemical reactions or in the creation of colour and our vision.