Phys.org September 6, 2022 While the impact of mechanical energy and heat on the friction and wear behavior of dry metallic interfaces has been the focus of extensive research in the past, the effect of extreme speeds on the near-surface deformation mechanisms in polycrystalline metals has remained poorly understood. An international team of researchers (Austria, UK) explored sliding velocities ranging from 10 to 2560 m/s via large-scale molecular dynamics simulations to identify three distinct deformation regimes in CuNi alloys. The microstructural response did not vary much for any of the considered systems up to sliding velocities of 40 m/s, but […]
The World Is Not Ready For The Next Super-Eruption, Scientists Warn
Science Alert September 6, 2022 According to researchers in the UK over the next century, large-scale volcanic eruptions are hundreds of times more likely to occur than are asteroid and comet impacts, put together. The peril posed by volcanoes may also be greater. In a 2021 study based on data from ancient ice cores, researchers found the intervals between catastrophic eruptions are hundreds or even thousands of years shorter than previously believed. The history of many volcanoes remains murky, making it hard to anticipate future eruptions and focus resources where risks are highest. According to the researchers we need more […]
Top 10 Science and Technology Inventions for the Week of September 2, 2022
01. Protein that could prevent chemical warfare attack created 02. From bits to p-bits: One step closer to probabilistic computing 03. Physicists develop a perfect light trap 04. Physicists entangle more than a dozen photons efficiently 05. Physicists uncover new dynamical framework for turbulence 06. Researchers use infrared light to wirelessly transmit power over 30 meters 07. Silicon image sensor that computes 08. Why ‘erasure’ could be key to practical quantum computing 09. Small molecules, giant (surface) potential 10. The US has ruled all taxpayer-funded research must be free to read. What’s the benefit of open access? And others… Master […]
From bits to p-bits: One step closer to probabilistic computing
Nanowerk August 29, 2022 To engineer probabilistic computers for more advanced computers researchers in Japan have developed a mathematical description to understand what happens to p-bits which could form the basis of probablistic computing. They utilized superparamagnetic tunnel junctions that have high sensitivity to external perturbations and determined the exponents through several independent measurements. They experimentally clarified the ‘switching exponent’ that governs fluctuation under the perturbations caused by magnetic field and spin-transfer torque in magnetic tunnel junctions. This gave them the mathematical foundation to implement magnetic tunnel junctions into the p-bit to sophisticatedly design probabilistic computers. They showed that these […]
Master equation to boost quantum technologies
Phys.org August 26, 2022 Measurement and feedback control are essential features of quantum science, with applications ranging from quantum technology protocols to information-to-work conversion in quantum thermodynamics. Theoretical descriptions of feedback control are typically given in terms of stochastic equations requiring numerical solutions or are limited to linear feedback protocols. An international team of researchers (Sweden, USA – University of Maryland, Switzerland) presented a formalism for continuous quantum measurement and feedback, both linear and nonlinear. The main result is a quantum Fokker-Planck master equation describing the joint dynamics of a quantum system and a detector with finite bandwidth. For fast […]
Months of gravity changes preceded the Tōhoku earthquake
Phys.org September 1, 2022 Researchers in France conducted a global analysis of Gravity Recovery and Climate Experiment (GRACE) reconstructed gravity gradients from July 2004 to February 2011 to test whether the deep signals preceding the March 2011 Tohoku earthquake could be detected before the event as a specific feature originating from solid Earth. They improved the angular resolution of the gravity gradients using two overlapping ranges of azimuthal sensitivity to investigate short-term signals of large amplitude aligned with the orientation of the Northwestern Pacific subduction and set-up a method to identify consistent solid Earth signals shared by different GRACE gravity […]
Neural networks predict forces in jammed granular solids
Phys.org September 1, 2022 Force chains are quasi-linear self-organised structures carrying large stresses and are ubiquitous in jammed amorphous materials like granular materials, foams or even cell assemblies. Understanding force chains is crucial in describing the mechanical and transport properties of granular solids and this applies in a wide range of circumstances—for example how sound propagates or how sand responds to mechanical deformation. Predicting where they will form upon deformation is crucial to describe the properties of such materials but remains an open question. An international team of researchers (Germany, Belgium, UK) demonstrated that graph neural networks (GNN) can accurately […]
Physics meets biology: How bacteria synchronize to build complex structures
Phys.org August 29, 2022 Observable characteristics—phenotypes—at the cellular scale underpins homeostasis and the fitness of living systems. However, how they shape properties at the population level remains poorly understood. An international team of researchers (Luxembourg, the Netherlands) found that phenotypic noise self-regulates with growth and coordinates collective structural organization, the kinetics of topological defects and the emergence of active transport around confluent colonies. They cataloged key phenotypic traits in bacteria growing under diverse conditions. The results revealed a statistically precise critical time for the transition from a monolayer biofilm to a multilayer biofilm, despite the strong noise in the cell […]
Physicists develop a perfect light trap
Phys.org August 25, 2022 One of the key insights of non-Hermitian photonics is that well-established concepts such as the laser can be operated in reverse to realize a coherent perfect absorber (CPA). Although conceptually appealing, such CPAs are limited so far to a single, judiciously shaped wavefront or mode. An international team of researchers (Israel, Austria) built a “light trap” around the thin layer using mirrors and lenses, in which the light beam is steered in a circle and then superimposed on itself—exactly in such a way that the beam of light blocks itself and can no longer leave the […]
Physicists entangle more than a dozen photons efficiently
Phys.org August 25, 2022 Optical photons represent ideal qubit carriers. However, the most successful technique so far for creating photonic entanglement is inherently probabilistic and, therefore, subject to severe scalability limitations. Researchers in Germany generated up to 14 entangled photons in a defined way and with high efficiency by using a single atom to emit the photons and interweave them in a very specific way, they placed a rubidium atom at the center of an optical cavity and triggered the emission of a photon that is entangled with the quantum state of the atom. By repeating the process several times […]