Working at nanoscale dimensions, billionths of a meter in size, a team of scientists led by the Department of Energy’s Oak Ridge National Laboratory revealed a new way to measure high-speed fluctuations in magnetic materials. Knowledge obtained by these new measurements, published in Nano Letters, could be used to advance technologies ranging from traditional computing to the emerging field of quantum computing.
Many materials undergo phase transitions characterized by temperature-dependent stepwise changes of important fundamental properties. Understanding materials’ behavior near a critical transition temperature is key to developing new technologies that take advantage of unique physical properties. In this study, the team used a nanoscale quantum sensor to measure spin fluctuations near a phase transition in a magnetic thin film. Thin films with magnetic properties at room temperature are essential for data storage, sensors and electronic devices because their magnetic properties can be precisely controlled and manipulated.
The team used a specialized instrument called a scanning nitrogen-vacancy center microscope at the Center for Nanophase Materials Sciences, a DOE Office of Science user facility at ORNL. A nitrogen-vacancy center is an atomic-scale defect in diamond where a nitrogen atom takes the place of a carbon atom, and a neighboring carbon atom is missing, creating a special configuration of quantum spin states. In a nitrogen-vacancy center microscope, the defect reacts to static and fluctuating magnetic fields, allowing scientists to detect signals on a single spin level to examine nanoscale structures.
In the past, events that took place in a flash were considered instantaneous. Yet modern experiments show that even when particles seem to shift in the blink of an eye, as with quantum entanglement, there are measurable intervals involved.
These findings spark questions about how electrons leave atoms or how entangled pairs form, opening avenues for precise control in various applications.
Scientists are diving into the deep sea to study one of the universe’s biggest mysteries—quantum gravity.
Using KM3NeT, a vast underwater neutrino telescope, researchers are watching ghost-like particles that may hold the key to uniting the physics of the very large and the very small. By analyzing how neutrinos oscillate—or don’t—during their journey through space, they’re searching for subtle signs of decoherence, a possible effect of quantum gravity.
A tiny particle and a big physics puzzle.
In the 1930s, researchers first noticed oddities in how galaxies moved, suggesting something invisible exerted gravitational pull. Decades later, studies of the cosmic microwave background —the lingering radiation from the universe’s birth—confirmed dark matter’s importance in shaping cosmic evolution.
A pivotal study by the Planck Collaboration in 2018 revealed that dark matter makes up roughly 27% of the universe’s total energy. By comparison, ordinary matter—the stuff of planets, stars, and us—accounts for only 5%.
Scientists have spent decades trying to understand what dark matter might be. Supersymmetry, a popular theory in particle physics, proposes a “partner” particle for every known particle, potentially offering clues about dark matter’s identity.
In a new development at CERN, researchers at the LHCb collaboration have determined the spin-parity of singly heavy charm baryons for the first time, addressing a long-standing mystery in baryon research.
Singly heavy baryons are particles containing one heavy quark—which in this case is a charm quark—and two light quarks. While the existence of these particles is not new, the exact nature of their excitation modes has remained elusive.
The study, published in Physical Review Letters, determined the nature by measuring the spin-parity of these charm baryons. Phys.org spoke to co-author Guanyue Wan, a Ph.D. Candidate at Peking University, China.
For the first time, scientists have directly measured the cross-section of a weak r-process nuclear reaction using a radioactive ion beam. Specifically, the team studied the reaction 94Sr(α, n)97Zr, where a radioactive isotope of strontium (strontium-94) absorbs an alpha particle (a helium nucleus), emits a neutron, and becomes zirconium-97.
The findings have been published as an Editors’ Suggestion in Physical Review Letters
<em> Physical Review Letters (PRL)</em> is a prestigious peer-reviewed scientific journal published by the American Physical Society. Launched in 1958, it is renowned for its swift publication of short reports on significant fundamental research in all fields of physics. PRL serves as a venue for researchers to quickly share groundbreaking and innovative findings that can potentially shift or enhance understanding in areas such as particle physics, quantum mechanics, relativity, and condensed matter physics. The journal is highly regarded in the scientific community for its rigorous peer review process and its focus on high-impact papers that often provide foundational insights within the field of physics.
Quantum technologies operate by leveraging various quantum mechanical effects, including entanglement. Entanglement occurs when two or more particles share correlated states even if they are distant.
When two particles are spin entangled, the intrinsic angular momentum (i.e., spin) of one particle can influence that of its entangled partner. This would suggest that the energy of the second particle can be altered via a nonlocal correlation, without enabling faster-than-light communication.
Researchers at Shanghai Jiao Tong University and Hefei National Laboratory recently carried out a study aimed at testing this theoretical prediction experimentally using two quantum memories.