Physicists at the University of Bayreuth and Johannes Gutenberg University Mainz have made a groundbreaking discovery that could transform the way we generate magnetic fields. Prof. Dr. Ingo Rehberg and Dr. Peter Blümler developed an innovative approach to create homogeneous magnetic fields using compact, permanent magnets. This breakthrough design outperforms the traditional Halbach arrangement, which is ideal only for infinitely long and therefore unrealizable magnets.

The new approach presents optimal three-dimensional arrangements of very compact magnets, idealized by point dipoles. The researchers investigated the optimal orientation of the magnets for two geometries relevant to practical use: a single ring and a stacked double ring. This “focused” design allows the generation of homogeneous fields outside the magnet plane, enabling applications such as magnetic levitation systems.

To validate their theoretical predictions, Rehberg and Blümler constructed magnet arrays from 16 FeNdB cuboids mounted on 3D-printed supports. The resulting magnetic fields were measured and compared with theoretical calculations, revealing excellent agreement. In terms of both magnetic field strength and homogeneity, the new configurations clearly outperform the classical Halbach arrangement.

The potential applications of this breakthrough design are vast. Conventional MRI technology relies on powerful superconducting magnets, which are technically complex and extremely costly. The new approach offers a promising alternative for generating homogeneous magnetic fields using permanent magnets. Additionally, this innovation could lead to advancements in particle accelerators and magnetic levitation systems.

This study was published in the renowned interdisciplinary journal Physical Review Applied, showcasing significant advances at the intersection of physics with engineering, materials science, chemistry, biology, and medicine. The implications of this breakthrough design are far-reaching, and further research is expected to uncover new possibilities for its applications.

The researchers at Rice University have made a groundbreaking discovery that vastly improves the stability of electrochemical devices converting carbon dioxide into useful fuels and chemicals. Their innovative approach involves simply sending the CO2 through an acid bubbler, which dramatically extends the operational life of these devices by more than 50 times.

Electrochemical CO2 reduction (CO2RR) is a promising green technology that uses electricity to transform climate-warming CO2 into valuable products like carbon monoxide, ethylene, or alcohols. These products can be further refined into fuels or used in industrial processes, potentially turning a major pollutant into a feedstock.

However, the practical implementation of this technology has been hindered by poor system stability due to salt buildup in gas flow channels. This issue occurs when potassium ions migrate from the anolyte across the anion exchange membrane to the cathode reaction zone and combine with CO2 under high pH conditions.

To combat this problem, the Rice team tried a clever twist on standard procedures. Instead of using water to humidify the CO2 gas input into the reactor, they bubbled the gas through an acid solution such as hydrochloric, formic, or acetic acid.

The vapor from the acid altered local chemistry in trace amounts, preventing salt crystallization and channel blockage. The effect was remarkable: systems operated stably for over 4,500 hours in a scaled-up electrolyzer, compared to just about 80 hours under standard water-humidified CO2 conditions.

This breakthrough has significant implications for the development of carbon capture and utilization technologies. By extending the lifespan of CO2 electrolyzers, this innovation can help make these technologies more commercially viable and sustainable.

The simplicity of this approach is noteworthy, as it requires only small tweaks to existing humidification setups, which means it can be adopted without significant redesigns or added costs. This makes it an attractive solution for industries looking to integrate carbon utilization technologies into their operations.

This work was supported by the Robert A. Welch Foundation, Rice University, the National Science Foundation, and the David and Lucile Packard Foundation. The researchers’ findings have the potential to transform the field of CO2RR and pave the way for more durable, scalable electrochemical devices that can efficiently convert CO2 into valuable products.

The study’s authors highlight the significance of this discovery, saying it “addresses a long-standing obstacle with a low-cost, easily implementable solution.” They also emphasize its potential impact on making carbon utilization technologies more commercially viable and sustainable.

Quantum sensors are getting increasingly sophisticated, and researchers at the University of Colorado Boulder have made a significant breakthrough in creating a device that can track 3D movement without relying on GPS. This innovative technology uses a cloud of atoms chilled to incredibly cold temperatures to measure acceleration in three dimensions – a feat that many scientists didn’t think was possible.

The device, a new type of atom “interferometer,” employs six lasers as thin as a human hair to pin a cloud of tens of thousands of rubidium atoms in place. With the help of artificial intelligence, the researchers manipulate those lasers in complex patterns, allowing them to measure the behavior of the atoms as they react to small accelerations – like pressing the gas pedal down in your car.

This new device is a marvel of engineering and has the potential to revolutionize navigation technology. If you leave a classical sensor out in different environments for years, it will age and decay. Atoms, on the other hand, don’t age, making them ideal for long-term use.

The researchers achieved this breakthrough by using laser interferometry, where they first shine a laser light, then split it into two identical beams that travel over two separate paths. They eventually bring the beams back together, and if the lasers have experienced diverging effects along their journeys, such as gravity acting in different ways, they may not mesh perfectly when they recombine.

The researchers achieved the same feat with atoms instead of light, using a device currently fitting on a bench about the size of an air hockey table. They cooled a collection of rubidium atoms down to temperatures just a few billionths of a degree above absolute zero, forming a mysterious quantum state of matter known as a Bose-Einstein Condensate (BEC).

The team then used laser light to jiggle the atoms, splitting them apart and creating a superposition – where each individual atom exists in two places at the same time. When the atoms snap back together, they form a unique pattern resembling a thumb print on a glass.

“We can decode that fingerprint and extract the acceleration that the atoms experienced,” said Murray Holland, professor of physics and fellow of JILA. The researchers spent almost three years building the device to achieve this feat, using an artificial intelligence technique called machine learning to streamline the process.

While the current experimental device is incredibly compact and has a long way to go before it can compete with traditional navigation tools, the technology is a testament to just how useful atoms can be. The group hopes to increase the performance of its quantum device many times over in the coming years, and their research opens up new possibilities for navigation technology based on atoms.