Science Alert August 7, 2023 On 28 October 2021, solar eruptions caused intense and long-lasting solar energetic particle (SEP) flux enhancements observed by spacecraft located over a wide longitudinal range in the heliosphere. SEPs arriving at Earth caused the 73rd ground level enhancement (GLE) event recorded by ground-based neutron monitors. This is also the first GLE event seen on the surface of three planetary bodies, Earth, Moon, and Mars, by particle and radiation detectors as shown in this study. An international team of researchers (China, Germany, Bulgaria, USA – Southwest Research Institute, Boulder, CO, industry, University of New Hampshire) derived […]
Top 10 Science and Technology Inventions for the Week of August 11, 2023
01. Super Radar: Breakthrough radar research overcomes a nearly century-old trade-off between wavelength and distance resolution 02. Quantum material exhibits ‘non-local’ behavior that mimics brain function 03. Thermal imaging innovation allows AI to see through pitch darkness like broad daylight 04. Discovering nanomachines within living organisms: Cytochromes P450 unleashed as living soft robots 05. A first-of-its-kind chip features both a laser and waveguide to create a photonic integrated circuit 06. Nanoelectromechanical resonators based on hafnia–zirconia–alumina superlattices with gigahertz spectrum coverage 07. New metalens lights the way for advanced control of quantum emission 08. New method simplifies the construction process for […]
Atomic-scale spin-optical laser: new horizon of optoelectronic devices
Nanowerk August 7, 2023 Researchers in Israel developed a spin-optical monolayer laser by incorporating a WS2 monolayer into a heterostructure microcavity supporting high-Q photonic spin-valley resonances. They generated the spin-valley modes from a photonic Rashba-type spin splitting of a bound state in the continuum, which gave rise to opposite spin-polarized ±K valleys due to emergent photonic spin–orbit interaction under inversion symmetry breaking. The laser showed intrinsic spin polarizations, high spatial and temporal coherence, and inherent symmetry-enabled robustness features, enabling valley coherence in the WS2 monolayer upon arbitrary pump polarizations at room temperature. According to the researchers their work on monolayer-integrated […]
Discovering nanomachines within living organisms: Cytochromes P450 unleashed as living soft robots
Phys.org August 7, 2023 An international team of researchers (Israel, India) addressed the difference between regular 3D matter and the nanomachines in ‘living matters’ (e.g., the CYP450 enzymes), which oxidize an array of essential substrate molecules. Molecular dynamics simulations revealed that, unlike 3D materials, CYP450s are 4D nanomachines, in which the fourth dimension was a sensing mechanism whereby the protein responds to an initial stimulus of substrate entrance and performs an autonomous chain of events (the catalytic cycle), which leads to substrate oxidation. They found that stimulus was the binding of a substrate molecule that eventually underwent oxidation in a […]
A first-of-its-kind chip features both a laser and waveguide to create a photonic integrated circuit
Phys.org August 9, 2023 To replace bulk optics and fibres in high-precision and highly coherent applications, ultralow-noise laser sources integrated with other photonic components in a compact and robustly aligned on a single chip are preferred. However, there are two major issues preventing the realization of such photonic integrated circuits: the high phase noise of semiconductor lasers and the difficulty of integrating optical isolators directly on-chip. An international team of researchers (USA – UC Santa Barbara, Caltech, industry, Egypt) leveraged three-dimensional integration that resulted in ultralow-noise lasers with isolator-free operation for silicon photonics. Through multiple monolithic and heterogeneous processing sequences, […]
Nanoelectromechanical resonators based on hafnia–zirconia–alumina superlattices with gigahertz spectrum coverage
Phys.org August 2, 2023 Nanomechanical resonators that can operate in the super high frequency (3–30 GHz) or the extremely high frequency (30–300 GHz) regime could be of use in the development of stable frequency references, wideband spectral processors, and high-resolution resonant sensors. However, such operation requires the dimensions of the mechanical resonators to be reduced to tens of nanometres, and current devices typically rely on transducers, for which miniaturization and chip-scale integration are challenging. Researchers at the University of Florida integrated nanoelectromechanical transducers created using 10-nm-thick ferroelectric hafnium zirconium oxide (Hf0.5Zr0.5O2) films on silicon and aluminium nitride membranes. They could yield resonators […]
New metalens lights the way for advanced control of quantum emission
Phys.org August 8, 2023 Traditional control of emission from quantum light sources relies on the use of multiple bulky optical elements or nanostructured resonators with limited functionalities, constraining the potential of multi-dimensional tailoring. An international team of researchers (Australia, South Korea) designed an ultrathin polarisation-beam-splitting metalens for the arbitrary structuring of quantum emission at room temperature. Due to the complete and independent polarisation and phase control at the single meta-atom level, the metalens enabled simultaneous mapping of quantum emission from ultra-bright defects in hexagonal boron nitride and imprinting of an arbitrary wavefront onto orthogonal polarisation states of the sources. The […]
New method simplifies the construction process for complex materials
MIT News August 2, 2023 Cellular metamaterials are small scale, tileable structures that can be architected to exhibit many useful material properties. But their “architectures” vary widely making it difficult to explore them using existing representations. An international team of researchers (USA – MIT, Austria) created a technique to include many different building blocks of cellular metamaterials into one, unified graph-based representation using which engineers can quickly and easily model metamaterials, edit the structures, and simulate their properties. Their procedural graph succinctly represents the construction process for any structure using a simple skeleton annotated with spatially varying thickness. To express […]
New technique measures structured light in a single shot
Phys.org August 8, 2023 Orbital angular momentum (OAM) spectrum diagnosis is a fundamental building block for diverse OAM-based systems. Among others, the simple on-axis interferometric measurement can retrieve the amplitude and phase information of complex OAM spectra in a few shots. Yet, its single-shot retrieval remains elusive, due to the signal–signal beat interference inherent in the measurement. Researchers in Switzerland have introduced the concept of Kramers–Kronig (KK) receiver in coherent communications to the OAM domain, enabling rigorous, single-shot OAM spectrum measurement. They explained in detail the working principle and the requirement of the KK method and applied the technique to […]
A novel laser slicing technique for diamond semiconductors
Nanowerk August 1, 2023 Laser slicing is a technique of slicing materials along cracks formed by scanning a focused ultrashort-pulse laser beam inside the materials. Researchers in Japan proposed a novel slicing technique to fabricate diamond wafers and demonstrate slicing at the {100} surface. Cracks parallel to the {100} plane are needed to fabricate the wafer. However, crystal materials contain a cleavage plane at the {111} plane, which cracks easily. Typically, cracks propagate not only along the {100} plane, which was the intended slicing plane, but also along the {111} plane, which increased the kerf loss. To restrict these undesirable […]