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Cosmological data suggest the universe has become ‘messier and more complicated’

Across cosmic history, powerful forces have acted on matter, reshaping the universe into an increasingly complex web of structures. Now, new research led by Joshua Kim and Mathew Madhavacheril at the University of Pennsylvania and their collaborators at Lawrence Berkeley National Laboratory suggests our universe has become “messier and more complicated” over the roughly 13.8 billion years it’s been around, or rather, the distribution of matter over the years is less “clumpy” than it should be expected.

“Our work cross-correlated two types of datasets from complementary, but very distinct, surveys,” says Madhavacheril, “and what we found was that, for the most part, the story of structure formation is remarkably consistent with the predictions from Einstein’s gravity. We did see a hint for a small discrepancy in the amount of expected clumpiness in recent epochs, around four billion years ago, which could be interesting to pursue.”

The data, which was published in the Journal of Cosmology and Astroparticle Physics and the preprint server arXiv, comes from the Atacama Cosmology Telescope’s (ACT) final data release (DR6) and the Dark Energy Spectroscopic Instrument’s (DESI) Year 1.

Bacteria found to eat forever chemicals, and even some of their toxic byproducts

In the quest to take the “forever” out of “forever chemicals,” bacteria might be our ally. Most remediation of per-and polyfluoroalkyl substances (PFAS) involves adsorbing and trapping them, but certain microbes can actually break apart the strong chemical bonds that allow these chemicals to persist for so long in the environment.

Now, a University at Buffalo-led team has identified a strain of bacteria that can break down and transform at least three types of PFAS, and perhaps even more crucially, some of the toxic byproducts of the bond-breaking process.

Published in this month’s issue of Science of the Total Environment, the team’s study found that Labrys portucalensis F11 (F11) metabolized over 90% of perfluorooctane (PFOS) following an exposure period of 100 days. PFOS is one of the most frequently detected and persistent types of PFAS and was designated hazardous by the U.S. Environmental Protection Agency last year.

Terahertz pulses induce chirality in a non-chiral crystal

Chirality refers to objects that cannot be superimposed onto their mirror images through any combination of rotations or translations, much like the distinct left and right hands of a human. In chiral crystals, the spatial arrangement of atoms confers a specific “handedness,” which—for example—influences their optical and electrical properties.

A Hamburg-Oxford team has focused on so-called antiferro-chirals, a type of non-chiral crystal reminiscent of antiferro-magnetic materials, in which anti-align in a staggered pattern leading to a vanishing net magnetization. An antiferro-chiral crystal is composed of equivalent amounts of left-and right-handed substructures in a unit cell, rendering it overall non-chiral.

The research team, led by Andrea Cavalleri of the Max-Planck-Institut for the Structure and Dynamics of Matter, used light to lift this balance in the non-chiral material boron phosphate (BPO4), in this way inducing finite chirality on an ultrafast time scale.

Study demonstrates integration of 1,024 silicon quantum dots with on-chip electronics all operating at low temperatures

Quantum computers have the potential of outperforming classical computers on some optimization tasks. Yet scaling up quantum computers leveraging existing fabrication processes while also maintaining good performances and energy-efficiencies has so far proved challenging, which in turn limits their widespread adoption.

Researchers at Quantum Motion in London recently demonstrated the integration of 1,024 independent silicon quantum dots with on-chip digital and analog electronics, to produce a quantum computing system that can operate at extremely low temperatures. This system, outlined in a paper published in Nature Electronics, links properties of devices at with those observed at room temperature, opening new possibilities for the development of silicon qubit-based technologies.

“As grow in complexity, new challenges arise such as the management of device variability and the interface with supporting electronics,” Edward J. Thomas, Virginia N. Ciriano-Tejel and their colleagues wrote in their paper.

Physicists propose ‘bridge’ strategy to stabilize quantum networks

While entangled photons hold incredible promise for quantum computing and communications, they have a major inherent disadvantage. After one use, they simply disappear.

In a new study, Northwestern University physicists propose a new strategy to maintain communications in a constantly changing, unpredictable quantum network. By rebuilding these disappearing connections, the researchers found the network eventually settles into a stable—albeit different—state.

The key resides in adding a sufficient number of connections to ensure the network continues to function, the researchers found. Adding too many connections comes with a high cost, overburdening the resources. But adding too few connections results in a fragmented network that cannot satisfy the user demand.

Protein denaturation provides a path toward more sustainable 3D printing of photoresins

The vast majority of photoresins for 3D printing (also referred to as additive manufacturing or AM) and related technologies are toxic, non-biodegradable, and sourced from unsustainable feedstocks. Non-traditional approaches to 3D printing offer a way to break free of the traditional confines of unsustainable petroleum-based reagents and chemical methods that require toxic monomers.

A recent collaboration between the University of Wisconsin’s Prof. AJ Boydston (Department of Chemistry) and Prof. Audrey Girard (Department of Food Science) has accomplished the first demonstration of via denaturation (AMPD).

The paper is published in the journal Green Chemistry.

A new method to fabricate soft electronics via particle engulfment printing

Perovskite solar cells are attracting attention as next-generation solar cells. These cells have high efficiency, are flexible, and can be printed, among other features. However, lead was initially used in their manufacture, and its toxicity has become an environmental issue.

Therefore, a method for replacing lead with tin, which has a low environmental impact, has been proposed. Nevertheless, tin is easily oxidized; consequently, the efficiency and durability of tin are lower than those of lead perovskite solar cells.

To improve the durability of tin perovskite by suppressing tin oxidation, a method that introduces large organic cations into tin perovskite crystals to form a two-dimensional layered structure called Ruddlesden-Popper (RP) tin-based perovskites has been proposed. However, the internal state of this structure and the mechanism by which it improves performance have not been fully elucidated.

Quantum thermometer uses giant Rydberg atoms to measure temperature more accurately

Scientists at the National Institute of Standards and Technology (NIST) have created a new thermometer using atoms boosted to such high energy levels that they are a thousand times larger than normal. By monitoring how these giant “Rydberg” atoms interact with heat in their environment, researchers can measure temperature with remarkable accuracy. The thermometer’s sensitivity could improve temperature measurements in fields ranging from quantum research to industrial manufacturing.

Unlike traditional thermometers, a Rydberg doesn’t need to be first adjusted or calibrated at the factory because it relies inherently on the basic principles of quantum physics. These fundamental quantum principles yield that are also directly traceable to international standards.

“We’re essentially creating a thermometer that can provide accurate temperature readings without the usual calibrations that current thermometers require,” said NIST postdoctoral researcher Noah Schlossberger.

Achromatic arbitrary polarization control in the terahertz band by tunable phase compensation

Polarization is a key parameter in light–matter interactions and is consequently closely linked to light manipulation, detection, and analysis. Terahertz (THz) waves, characterized by their broad bandwidth and long wavelength, pose significant challenges to efficient polarization control with existing technologies. Here, we leverage the mesoscale wavelength characteristics of THz waves and employ a mirror-coupled total internal reflection structure to mechanically modulate the phase difference between p-and s-waves by up to 289°. By incorporating a liquid crystal phase shifter to provide adaptive phase compensation, dispersion is eliminated across a broad bandwidth. We demonstrate active switching of orthogonal linear polarizations and handedness-selective quarter-wave conversions in the 1.6–3.4 THz range, achieving an average degree of linear/circular polarization exceeding 0.996. Furthermore, arbitrary polarization at any center frequency is achieved with a fractional bandwidth exceeding 90%. This customizable-bandwidth and multifunctional device offers an accurate and universal polarization control solution for various THz systems, paving the way for numerous polarization-sensitive applications.