Lifeboat Foundation

Abstract: Scientists have looked for different ways to force hydrogen into a metallic state for decades. A metallic state of hydrogen is a holy grail for materials science because it could be used for superconductors, materials that have no resistance to the flow of electrons, which increases electricity transfer efficiency many times over. For the first time researchers, led by Carnegie’s Viktor Struzhkin, have experimentally produced a new class of materials blending hydrogen with sodium that could alter the superconductivity landscape and could be used for hydrogen-fuel cell storage. The research is published in Nature Communications.

It had been predicted that certain hydrogen-rich compounds consisting of multiple atoms of hydrogen with so-called alkali metals like lithium, potassium or sodium, could provide a new chemical means to alter the compound’s electronic structure. This, in turn, may lead the way to metallic high-temperature superconductors.

“The challenge is temperature,” explained Struzhkin. “The only superconductors that have been produced can only exist at impractically cold temperatures. In recent years, there have been predictions of compounds with several atoms of hydrogen coupled with alkali metals that could exist at more practical temperatures. They are theorized to have unique properties useful to superconductivity.”

Among the intriguing issues in plasma physics are those surrounding X-ray pulsars—collapsed stars that orbit around a cosmic companion and beam light at regular intervals, like lighthouses in the sky. Physicists want to know the strength of the magnetic field and density of the plasma that surrounds these pulsars, which can be millions of times greater than the density of plasma in stars like the sun.

Researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have developed a theory of plasma waves that can infer these properties in greater detail than in standard approaches. The new research analyzes the plasma surrounding the pulsar by coupling Einstein’s theory of relativity with quantum mechanics, which describes the motion of subatomic particles such as the atomic nuclei—or ions—and electrons in plasma. Supporting this work is the DOE Office of Science.

Quantum field theory

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If biochemists had access to a quantum computer, they could perfectly simulate the properties of new molecules to develop drugs in ways that would take today’s fastest computers decades. A new device takes us closer to providing such a computer. The device successfully traps, detects, and manipulates an ensemble of electrons above the surface of superfluid helium. The system integrates a nanofluidic channel with a superconducting circuit.

Because they are so small, electrons normally interact weakly with electrical signals. The new device, however, gives the electron more time to interact, and it is this setup that makes it possible to build a qubit, the quantum computing equivalent of a bit. Quantum computers could provide the necessary computing power to model extremely large and complex situations in physics, biology, weather systems and many others.

While isolated electrons in a vacuum can store quantum information nearly perfectly, in real materials, the movements of surrounding atoms disturbs them, eventually leading to the loss of information. This work is a step towards realizing isolated, trapped single electrons by taking advantage of the unique relationship existing between electrons and superfluid helium. Electrons will levitate just above the surface of helium, about 10 nanometers away, insensitive to the atomic fluctuations below. While this effect has been known, holding them in a superconducting device structure has not been demonstrated before this work. At the heart of this new technology is a resonator based on circuit quantum electrodynamics (cQED) architecture, which provides a path to trap electrons above helium and detect the spins of the electrons. Because they are so small, electrons normally interact only very weakly with electrical signals.

Is light a wave or a particle? Yes.

In December of last year, scientists at the Large Hadron Collider in Europe announced startling results hinting at the existence of an undiscovered subatomic particle—one with a mass six times heavier than the Higgs boson, the particle that made headlines in 2012.

The evidence is still thin, but if more data confirm the finding, it could sharpen humankind’s understanding of the building blocks of the universe.

“This was a very surprising announcement and a puzzle at the same time, because the lifetime and mass of the particle could reveal something else beyond simply one extra particle, if it turns out to be a real signal,” said Kyoungchul “K.C.” Kong, associate professor of physics and astronomy at the University of Kansas. “Yet we do not claim this as a discovery, and we need more data.”

Continue reading “Physicist offers leading theory about mysterious Large Hadron Collider excess” »

“Another very good test some readers may want to look up… is the Casimir effect, where forces between metal plates in empty space are modified by the presence of virtual particles.” –Gordon Kane

If you ask what the zero-point energy of space itself is, you can sum up all of the quantum fluctuations you can that arise in quantum field theory, and arrive at an absurd answer: 120 orders of magnitude greater than the observed. Yet if you assume that there’s an incredible cancellation and you get exactly zero, that removes the one thing our Universe needs to explain its expansion: dark energy.

The realization of reconfigurable modular microrobots could aid drug delivery and microsurgery by allowing a single system to navigate diverse environments and perform multiple tasks. So far, microrobotic systems are limited by insufficient versatility; for instance, helical shapes commonly used for magnetic swimmers cannot effectively assemble and disassemble into different size and shapes. Here by using microswimmers with simple geometries constructed of spherical particles, we show how magnetohydrodynamics can be used to assemble and disassemble modular microrobots with different physical characteristics. We develop a mechanistic physical model that we use to improve assembly strategies. Furthermore, we experimentally demonstrate the feasibility of dynamically changing the physical properties of microswimmers through assembly and disassembly in a controlled fluidic environment. Finally, we show that different configurations have different swimming properties by examining swimming speed dependence on configuration size.

A result from an experiment in Hungary catches the attention of a group of theorists in the United States.

Finally, portable thermal imaging devices could be here soon.

The primary source of infrared radiation is heat—the radiation produced by the thermal motion of charged particles in matter, including the motion of the atoms and molecules in an object. The higher the temperature of an object, the more its atoms and molecules vibrate, rotate, twist through their vibrational modes, the more infrared radiation they radiate. Because infrared detectors can be “blinded” by their own heat, high-quality infrared sensing and imaging devices are usually cooled down, sometimes to just a few degrees above absolute zero. Though they are very sensitive, the hardware required for cooling renders these instruments less-than-mobile, energy-inefficient and limits in-the-field applications.

A paper published this week in the journal Optics Express, from The Optical Society (OSA), describes a new type of portable, field-friendly, mid-infrared detector that operates at room temperature. Room-temperature operation, notes Andreas Harrer of the TU-Wien Center for Micro- and Nanostructures, Austria and the first author of the paper, “is essential for detectors to be energy-efficient enough for portable and handheld applications. We want to pave the way to an infrared-detection technology which is flexible in design and meets all requirements for compact integrated field-applicable detection systems.”

Continue reading “Pixel-array quantum cascade detector paves the way for portable thermal imaging devices” »