Imagine watching a speaker and another person nearby is loudly crunching from a bag of chips. To deal with this, a person could adjust their attention to downplay those crunch noises or focus their hearing on the speaker. But understanding how human brains do this has been a challenge.
Scientists are racing to develop new materials for quantum technologies in computing and sensing for ultraprecise measurements. For these future technologies to transition from the laboratory to real-world applications, a much deeper understanding is needed of the behavior near surfaces, especially those at interfaces between materials.
Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have unveiled a new technique that could help advance the development of quantum technology. Their innovation, surface-sensitive spintronic terahertz spectroscopy (SSTS), provides an unprecedented look at how quantum materials behave at interfaces.
The work is published in the journal Science Advances.
Researchers at North Carolina State University have demonstrated a new technique that uses light to tune the optical properties of quantum dots—making the process faster, more energy-efficient and environmentally sustainable—without compromising material quality.
The findings are published in the journal Advanced Materials.
“The discovery of quantum dots earned the Nobel Prize in chemistry in 2023 because they are used in so many applications,” says Milad Abolhasani, corresponding author of a paper on the work and ALCOA Professor of Chemical and Biomolecular Engineering at NC State. “We use them in LEDs, solar cells, displays, quantum technologies and so on. To tune their optical properties, you need to tune the bandgap of quantum dots—the minimum energy required to excite an electron from a bound state to a free-moving state—since this directly determines the color of light they emit.
Atomic nuclei exhibit multiple energy scales simultaneously—ranging from hundreds down to fractions of a megaelectronvolt. A new study demonstrates that these drastically different scales can be explained through calculations based on the strong nuclear force. The research also predicts that the atomic nucleus neon-30 exhibits several coexisting shapes.
“This discovery is incredibly important for understanding the stability limits of visible matter and how they can be anchored in our theory of the strong force,” says Christian Forssén, professor at the Department of Physics at Chalmers University of Technology.
Together with Andreas Ekström, professor at the same department, they have been part of the research group that has now published their findings in Physical Review X. In addition to Chalmers, the researchers behind the study are active at Oak Ridge National Laboratory and the University of Tennessee in the United States.
Physicists have found a simple and effective way to skip over an energy level in a three-state system, potentially leading to increased quantum computational power with fewer qubits.
Nearly a century ago, Lev Landau, Clarence Zener, Ernst Stückelberg, and Ettore Majorana found a mathematical formula for the probability of jumps between two states in a system whose energy is time-dependent. Their formula has since had countless applications in various systems across physics and chemistry.
Now physicists at Aalto University’s Department of Applied Physics have shown that the jump between different states can be realized in systems with more than two energy levels via a virtual transition to an intermediate state and by a linear chirp of the drive frequency. This process can be applied to systems where it is not possible to modify the energy of the levels.
Researchers have announced results from a new search at the European X-ray Free Electron Laser (European XFEL) Facility at Hamburg for a hypothetical particle that may make up the dark matter of the universe. The experiment is described in a study published in Physical Review Letters.
This experiment looks for axions, a particle which was proposed to solve a major problem in particle physics: why neutrons, although composed of smaller charged particles called quarks, do not possess an electric dipole moment. To explain this, it was suggested that axions, tiny and incredibly light particles, can “cancel out” this imbalance. If observed, this process would provide direct evidence for new physics beyond the Standard Model.
Additionally, axions turn out to be a natural candidate for dark matter, the mysterious substance that constitutes most of the structure of the universe.
When it comes to layered quantum materials, current understanding only scratches the surface; so demonstrates a new study from the Paul Scherrer Institute PSI. Using advanced X-ray spectroscopy at the Swiss Light Source SLS, researchers uncovered magnetic phenomena driven by unexpected interactions between the layers of a kagome ferromagnet made from iron and tin. This discovery challenges assumptions about layered alloys of common metals, providing a starting point for developing new magnetoelectric devices and rare-earth-free motors.
The research is published in the journal Nature Communications.
Patterns are everything. With quantum materials, it’s not just what they’re made of but how their atoms or molecules are organized that gives rise to the exotic properties that excite researchers with their promise for future technologies.
Many objects that we normally deal with in quantum physics are only visible with special microscopes—individual molecules or atoms, for example. However, the quantum objects that Elena Redchenko works with at the Institute for Atomic and Subatomic Physics at TU Wien can even be seen with the naked eye (with a little effort): They are hundreds of micrometers in size. Still tiny by human standards but gigantic in terms of quantum physics.
Those huge quantum objects are superconducting circuits —structures in which electric current flows at low temperatures without any resistance. In contrast to atoms, which have fixed properties, determined by nature, these artificial structures are extremely customizable and allow scientists to study different physical phenomena in a controlled manner. They can be seen as “artificial atoms,” whose physical properties can be adjusted at will.
By coupling them, a system was created that can be used to store and retrieve light—an important prerequisite for further quantum experiments. This experiment was carried out in the group of Johannes Fink at ISTA, with theoretical collaboration from Stefan Rotter at the Institute for Theoretical Physics at TU Wien. The results have now been published in the journal Physical Review Letters.
A collaborative study published in Nature reveals an innovative strategy to enhance energy storage in antiferroelectric materials.
The study, conducted by researchers from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, Tsinghua University, Songshan Lake Materials Laboratory, and the University of Wollongong, introduces the antipolar frustration strategy, which significantly improves the performance of dielectric capacitors that are crucial for high-power devices requiring fast charge and discharge rates.
Antiferroelectrics, which feature an antiparallel polarization configuration, are emerging as promising materials for energy storage due to their phase transition from antiferroelectric to ferroelectric under an electric field. This transition provides high polarization strength and near-zero remanent polarization, ideal for energy storage.
An international team of scientists has unveiled new insights into the dissociation dynamics of sulfur hexafluoride (SF6) under high-energy X-ray excitation. The study, conducted using advanced synchrotron radiation techniques, sheds light on the formation of neutral sulfur atoms during the decay of deep core holes in SF6. The work is published in Physical Review Letters.
Understanding the interaction of X-rays with matter is fundamental to both scientific research and practical applications, including medical and technological advancements. These interactions involve complex processes including absorption, ionization, scattering, and the decay of excited states, which emit electrons or photons.
In 1978, young scientists named Joseph Nordgren and Hans Ågren discovered an unusual spectral feature in sulfur hexafluoride (SF6) that defied explanation at the time. Their discovery was made at the Siegbahn Laboratory of Uppsala University, founded by the late Nobel Prize laureate Kai Siegbahn. Despite further investigations, the nature of this spectral anomaly remained unclear.