Lifeboat Foundation

Cooling atoms to ultracold temperatures is a routine task in atomic physics labs, but molecules are a trickier proposition. Researchers in the US have now used a widely-applicable combination of methods to make molecules colder than ever before – a feat that could pave the way for applications in areas as diverse as high-temperature superconductivity and quantum computing.

In everyday life, we do not see the bizarre effects of quantum mechanics because the quantum states of the particles around us are constantly collapsing, or decohering, as they interact. At temperatures near absolute zero, however, some identical particles will simultaneously occupy the lowest energy quantum state available. This phenomenon is known as quantum degeneracy, and it was experimentally demonstrated in 1995, when groups led by Eric Cornell and Carl Wieman (then at the University of Colorado, Boulder) and Wolfgang Ketterle of the Massachusetts Institute of Technology (MIT) created the first Bose-Einstein condensates (BECs) with rubidium and sodium atoms, respectively.

Other groups have subsequently made condensates using other atomic species, and various techniques have been developed to cool atoms to quantum degeneracy. In one of the simplest methods, a sample of atoms is confined in a magnetic or optical trap. Hotter atoms with more kinetic energy are more readily able to escape, or evaporate, from this trap, so the remaining atoms become cooler. In another method, known as sympathetic cooling, one type of atom is cooled directly and allowed to thermalize with atoms of another type, thereby cooling them by extracting their kinetic energy.

How did matter gain the edge over antimatter in the early universe? Maybe, just maybe, neutrinos.

The Super-Kamiokande Neutrino Observatory, located more than 3,000 feet below Mount Ikeno near the city of Hida, Japan. Credit… Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo.

We present a calculation of a neutrino decay scenario in the early Universe. The specific decay is ν_{2} \to ν_{1} + ϕ, where ϕis a boson. If there is a neutrino mass hierarchy, m_{ν_{e}} m_{ν_μ} m_{ν_τ}, we show that it is possible to generate stimulated decay and effects similar to atomic lasing without invoking new neutrinos, even starting from identical neutrino distributions. Under the right circumstances the decay can be to very low momentum boson states thereby producing something similar to a Bose condensate, with possible consequences for structure formation. Finally, we argue that this type of decay may also be important other places in early Universe physics.

Scientists have studied this ebb and flow for centuries, but only began understanding its effects on our planet at the dawn of the space age in the mid-20th century. Now it is clear that around solar maximum the sun is more likely to bombard Earth with charged particles that damage satellites and power grids. The solar cycle also plays a minor role in climate, as variations in irradiance can cause slight changes in average sea-surface temperatures and precipitation patterns. Thus, a better understanding of the cycle’s physical drivers is important for sustainable living on Earth.

Yet scientists still lack a model that perfectly predicts the cycle’s key details, such as the exact duration and strength of each phase. “I think the solar cycle is so stable and clear that there is something fundamental that we are missing,” says Ofer Cohen, a solar physicist at the University of Massachusetts Lowell. One obstacle to figuring it out, he says, is that crucial details of the apparent mechanisms behind the cycle—such as the sun’s magnetic field—are largely hidden from our view. But that might be about to change.

Tim Linden, an astronomer at The Ohio State University, and his colleagues recently mapped how the sun’s high-energy glow dances across its face over time. They found a potential link between these high-energy emissions, the sun’s fluctuating magnetic field and the timing of the solar cycle. This, many experts argue, could open a new window into the inner workings of our nearest, most familiar star.

The antimicrobial properties of silver have been known for centuries. While it is still a mystery as to exactly how silver kills bacteria, University of Arkansas researchers have taken a step toward better understanding the process by looking at dynamics of proteins in live bacteria at the molecular level.

Traditionally, the antimicrobial effects of silver have been measured through bioassays, which compare the effect of a substance on a test organism against a standard, untreated preparation. While these methods are effective, they typically produce only snapshots in time, said Yong Wang, assistant professor of physics and an author of the study, published in the journal Applied and Environmental Microbiology.

Instead, Wang and his colleagues used an advanced imaging technique, called “single-particle-tracking photoactivated localization microscopy,” to watch and track a particular protein found in E. coli bacteria over time.

The first official evidence of a key imbalance between neutrinos and antineutrinos provides one of the best clues for why the universe contains something rather than nothing.

PsiQuantum is a little-known quantum computing startup, however it recently had no trouble raising almost a quarter of a billion dollars from Microsoft’s M12 venture fund and other investors. That is in addition to a whopping $230 million it received last year from a fund formed by Andy Rubin, developer of the Android operating system.

The company was founded in 2016 by British professor Jeremy O’Brien and three other academics, Terry Rudolph, Mark Thompson, and Pete Shadbolt. In just a few years, they have quietly grown the company from a few employees to a robust technical staff of more than 100.

Compared to today’s modest quantum computing capabilities, PsiQuantum’s elevator pitch for investors sounds like a line from a science fiction movie. O’Brien not only says he is going to build a fault-tolerant quantum computer with a staggering one million qubits, he also says he is going to do it within five years. O’Brien’s technology of choice for this claim is silicon photonics, which uses particles of light called photons to perform quantum calculations. Theoretically, photons behave as both waves and particles, but that’s a subject for another article. Quantum computing technologies in use today are primarily superconductors and trapped ion. However, there is plenty of research that shows photonics holds a lot of promise.

A major finding in particle physics reminds us of the importance of robust preliminary results — and paves the way for more exciting discoveries.

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Metasurfaces are artificial materials designed at the nanoscale, which can control the scattering of light with exceptionally high precision. Over the past decade or so, these materials have been used to create a variety of technological tools ranging from sensors to lenses and imaging techniques.

A research team led by Mikhail Lukin at Harvard University has recently proposed a new type of metasurface that can control both the spatiotemporal and quantum properties of transmitted and reflected light. In a paper published in Nature Physics, the team showed that realizing a quantum metasurface is possible and could be achieved by entangling the macroscopic response of thin atom arrays to light.

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