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After several years of developing the theoretical ideas, University of Illinois Urbana-Champaign researchers have validated multiple novel predictions about the fundamental mechanism of transport of atoms and molecules (penetrants) in chemically complex molecular and polymer liquid matrices.

The study from Materials Science and Engineering (MatSE) Professor Ken Schweizer and Dr. Baicheng Mei, published recently in Proceedings of the National Academy of Sciences (PNAS), extended the theory and tested it against a large amount of experimental data. MatSE Associate Professor Chris Evans and graduate student Grant Sheridan collaborated on this research by providing additional experimental measurements.

“We developed an advanced, state-of-the art theory to predict how molecules move through complex media, especially in polymer liquids,” Schweizer said. “The theory abstracted what the important features are of the chemically complex molecules and of the polymeric medium that they’re moving through that control their rate of transport.”

Chirality is the breaking of reflection and inversion symmetries. Simply put, it is when an object’s mirror images cannot be superimposed over each other. A common example are your two hands—while mirror images of each other, they can never overlap. Chirality appears at all levels in nature and is ubiquitous.

In addition to static chirality, chirality can also occur due to dynamic motion including rotation. With this in mind, we can distinguish true and false chirality. A system is truly chiral if—when translating—space inversion does not equate to time reversal combined with a proper spatial rotation.

Phonons are quanta (or small packets) of energy associated with the vibration of atoms in a crystal lattice. Recently, phonons with chiral properties have been theorized and experimentally discovered in two-dimensional (2D) materials such as tungsten diselenide. The discovered chiral phonons are rotating—yet not propagating—atomic motions. But, truly chiral phonons would be atomic motions that are both rotating and propagating, and these have never been observed in three-dimensional (3D) bulk systems.

Vibrating tiny robots could revolutionize research.

Individual robots can work collectively as swarms to create major advances in everything from construction to surveillance, but microrobots’ small scale is ideal for drug delivery, disease diagnosis, and even surgeries.

Despite their potential, microrobots’ size often means they have limited sensing, communication, motility, and computation abilities, but new research from the Georgia Institute of Technology enhances their ability to collaborate efficiently. The work offers a new system to control swarms of 300 3-millimeter microbristle robots’ (microbots) ability to aggregate and disperse controllably without onboard sensing.

Organic photovoltaics, solar energy devices based on organic semiconductors, have so far achieved very promising results in experimental settings, both in terms of efficiency and stability. However, engineers have not yet devised reliable strategies to fabricate these devices on a large-scale at a reasonable cost.

Researchers at Wuhan University in China have recently identified an approach that could facilitate the rapid fabrication of photoactive layers for organic solar cells, without compromising the cells’ efficiency and stability. Their proposed strategy, introduced in a paper published in Nature Energy, is based on sequential deposition, a method often used to deposit organic semiconductors and perovskite films on substrates.

“To realize the commercialization of organic photovoltaics (OPVs), the golden triangle of power conversion efficiency (PCE), stability, and cost should be considered simultaneously,” Jie Min, one of the researchers who carried out the study, told TechXplore.

A new and more efficient way of modeling and designing power electronic converters using artificial intelligence (AI) has been created by a team of experts from Cardiff University and the Compound Semiconductor Applications (CSA) Catapult.

The method has reduced design times for technology by up to 78% compared to traditional approaches and was used to create a device with an efficiency of over 98%.

The team’s findings have been published in the IEEE Open Journal of Power Electronics and IEEE Transactions on Power Electronics.

A series of demonstrations by Micius—a low-orbit satellite with quantum capabilities—lays the groundwork for a satellite-based quantum communication network.

Few things have captured the scientific imagination quite like the vastness of space and the promise of quantum technology. Micius—the Chinese Academy of Science’s quantum communications satellite launched in 2016—has connected these two inspiring domains, producing a string of exciting first demonstrations in quantum space communications. Reviewing the efforts leading up to the satellite launch and the major outcomes of the mission, Jian-Wei Pan and colleagues at the University of Science and Technology of China provide a perspective on what the future of quantum space communications may look like [1]. The success of this quantum-satellite mission proves the viability of several space-based quantum communications protocols, providing a solid foundation for future improvements that may lead to an Earth-spanning quantum communications network (Fig. 1).

Photons, the quanta of light, are wonderful carriers of quantum information because they are easy to manipulate and travel extremely fast. They can be created in a desired quantum state or as the output of some quantum sensor or quantum computer. Quantum entanglement between multiple photons—the nonclassical correlation between their quantum states—can be amazingly useful in quantum communications protocols such as quantum key distribution (QKD), a cryptography approach that can theoretically guarantee absolute information security. QKD schemes have been demonstrated on distances of a few hundreds of kilometers—sufficient to cover communications networks between cities. But increasing their range, eventually to the global scale, is a formidable challenge.

A new quantum random-access memory device reads and writes information using a chirped electromagnetic pulse and a superconducting resonator, making it significantly more hardware-efficient than previous devices.

Random-access memory (or RAM) is an integral part of a computer, acting as a short-term memory bank from which information can be quickly recalled. Applications on your phone or computer use RAM so that you can switch between tasks in the blink of an eye. Researchers working on building future quantum computers hope that such systems might one day operate with analogous quantum RAM elements, which they envision could speed up the execution of a quantum algorithm [1, 2] or increase the density of information storable in a quantum processor. Now James O’Sullivan of the London Centre for Nanotechnology and colleagues have taken an important step toward making quantum RAM a reality, demonstrating a hardware-efficient approach that uses chirped microwave pulses to store and retrieve quantum information in atomic spins [3].

Just like quantum computers, experimental demonstrations of quantum memory devices are in their early days. One leading chip-based platform for quantum computation uses circuits made from superconducting metals. In this system, the central processing is done with superconducting qubits, which send and receive information via microwave photons. At present, however, there exists no quantum memory device that can reliably store these photons for long times. Luckily, scientists have a few ideas.

A magnetic field can significantly boost the performance of a large-scale fusion experiment that may lead to a future source of clean power.

Nuclear fusion could provide a clean power source, but one of the technological challenges is maintaining the fuel at a high enough temperature for a long enough time. In a technique called inertial confinement fusion (ICF)—where lasers initiate the nuclear reaction—a magnetic field has been shown to improve heating. Now researchers have shown that a magnetic field can also help in a large-scale experiment with a more complicated design that produces far more energy [1]. The applied field increased the fuel’s temperature by 40% and tripled the fusion reaction’s efficiency. The work provides a step toward increasing the robustness and energy output of the fusion reaction and provides the first proof of concept of magnetization-assisted fusion in a large-scale experiment.

In the simplest version of ICF, synchronized laser pulses hit a capsule filled with cold hydrogen fuel, causing it to implode. The implosion heats the fuel and creates a spot of burning plasma (see Viewpoint: Fusion Turns Up the Heat). The “hot spot” serves as a spark that initiates burning throughout the fuel, driving a self-sustaining fusion reaction that releases energy. However, these implosions can fail to generate significant fusion energy if the fuel pellet has small imperfections on its surface or if the lasers are not perfectly timed. But if the fuel could be heated to temperatures higher than was possible in recent experiments, there would be more margin for error, which could alleviate the sensitivity to such details.

The observation of the onset of turbulence in a gas of bosons allows researchers to explore how turbulence comes to life.

Despite over a century of trying, physicists have yet to develop a complete theory of turbulence—the complex, chaotic motion of a fluid. Now Maciej Gałka of the University of Cambridge and colleagues have taken a step in that direction by witnessing the onset of turbulence in a quantum gas and observing its evolution over roughly 100 ms [1]. The finding could help scientists answer open questions in turbulence, which is observed in systems ranging from ocean waves to star interiors.