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Category: particle physics – Page 259

What if we could create metal made of water? Pure water itself is almost perfect as an insulator. Water found naturally in the world is a perfect conduit for electricity due to the impurities and minerals found within it. But water only becomes “metallic” at extremely high pressures. Now researchers have found a way to do so by metallicizing pure water using certain metals.

The process was first experimented with for a paper researchers published in July of 2021. Now, though, a group of researchers have managed to record the transformation of water into metal and shared the video on YouTube. The transformation is only made possible by bringing pure water into contact with electron-sharing alkali metals.

In this instance, the researchers used a combination alloy made of sodium and potassium and then added free-moving charged particles. To accomplish the transformation and create metal from water, the researchers exposed a drop of the alloy to a small amount of water vapor in a vacuum chamber. The water vapor then began to condense on the surface, expanding the droplet altogether.

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Improved fabrication methods for qubits made from erbium-doped silicon waveguides give these qubits the key prerequisites for becoming a contender for future quantum computers.

From superconducting circuits to single atoms, there are many quantum-bit—or “qubit”—systems to choose from when building a quantum computer. New to the game are qubits made from individual erbium atoms implanted in silicon waveguides. Each of these qubits can be controlled and measured with telecom-wavelength light, making the platform practical to implement. But the platform has unfavorable properties that have put that implementation on hold. Now Andreas Reiserer of the Max Planck Institute of Quantum Optics in Germany and his colleagues have improved the qubit’s fabrication and detection methods, such that it is viable for near-future use in quantum computing technologies [1]. The results suggest that erbium-doped silicon waveguides could make more promising qubits than previously thought.

One problem with previous erbium-doped silicon waveguides came from the uneven clustering of erbium atoms around impurities in the waveguide. This clustering meant that the erbium atoms had different transition frequencies, making it difficult to simultaneously address multiple atoms and to perform basic operations between them—a necessary component of quantum information processing.

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Light-pulse matter-wave interferometers exploit the quantized momentum kick given to atoms during absorption and emission of light to split atomic wave packets so that they traverse distinct spatial paths at the same time. Additional momentum kicks then return the atoms to the same point in space to interfere the two matter-wave wave packets. The key to the precision of these devices is the encoding of information in the phase ϕ that appears in the superposition of the two quantum trajectories within the interferometer. This phase must be estimated from quantum measurements to extract the desired information. For N atoms, the phase estimation is fundamentally limited by the independent quantum collapse of each atom to an r.m.s. angular uncertainty \(\Delta {\theta }_{{\rm{SQL}}}=1/\sqrt{N}\) rad, known as the standard quantum limit (SQL)2.

Here we demonstrate a matter-wave interferometer31,32 with a directly observed interferometric phase noise below the SQL, a result that combines two of the most striking features of quantum mechanics: the concept that a particle can appear to be in two places at once and entanglement between distinct particles. This work is also a harbinger of future quantum many-body simulations with cavities26,27,28,29 that will explore beyond mean-field physics by directly modifying and probing quantum fluctuations or in which the quantum measurement process induces a phase transition30.

Quantum entanglement between the atoms allows the atoms to conspire together to reduce their total quantum noise relative to their total signal1,3. Such entanglement has been generated between atoms using direct collisional33,34,35,36,37,38,39 or Coulomb40,41 interactions, including relative atom number squeezing between matter waves in spatially separated traps33,35,39 and mapping of internal entanglement onto the relative atom number in different momentum states42. A trapped matter-wave interferometer with relative number squeezing was realized in ref. 35, but the interferometer’s phase was antisqueezed and thus the phase resolution was above the SQL.

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Physicists have created the first Bose-Einstein condensate—the mysterious fifth state of matter—made from quasiparticles, entities that do not count as elementary particles but that can still have elementary-particle properties like charge and spin. For decades, it was unknown whether they could undergo Bose-Einstein condensation in the same way as real particles, and it now appears that they can. The finding is set to have a significant impact on the development of quantum technologies including quantum computing.

A paper describing the process of creation of the substance, achieved at temperatures a hair’s breadth from absolute zero, was published in the journal Nature Communications.

Bose-Einstein condensates are sometimes described as the fifth state of matter, alongside solids, liquids, gases and plasmas. Theoretically predicted in the early 20th century, Bose-Einstein condensates, or BECs, were only created in a lab as recently as 1995. They are also perhaps the oddest state of matter, with a great deal about them remaining unknown to science.

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A type of aurora briefly tore a 400 km wide hole in Earth’s ozone layer.

An international team of researchers showed that a certain type of aurora called the “Isolated proton aurora” depletes our atmosphere’s ozone layer. They discovered a nearly 250-mile-wide (400 kilometers) hole in the ozone layer right above where an aurora occurred. Before now, the influence of these particles was only vaguely known. The study is published in Scientific reports.

What causes the auroras?

Solar storms on the sun’s surface give out huge clouds of electrically charged particles. These particles can travel millions of miles, and some may eventually collide with the Earth. Most of these particles are deflected away, but some become captured in the Earth’s magnetic field. When they are entrapped, their charge ionizes the atmosphere and produces nitrogen oxides and hydrogen oxides. Both compounds contribute to ozone loss.

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Astronomers have discovered a mysterious neutron star that’s far lighter than previously thought possible, undermining our understanding of the physics and evolution of stars. And fascinatingly, it may be composed largely of quarks.

As detailed in a new paper published in the journal Nature Astronomy this week, the neutron star has a radius of just 6.2 miles and only the mass of 77 percent of the Sun.

That makes it much lighter than other previously studied neutron stars, which usually have a mass of 1.4 times the mass of the Sun at the same radius.

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