Science Alert February 4, 2024 The existence of alternate mechanisms for magnetism that could naturally facilitate electrical control has been discussed theoretically but an experimental demonstration has not been done. An international team of researchers (Switzerland, Spain, US -University of Tennessee, Japan) investigated MoSe2/WS2 van der Waals heterostructures in the vicinity of Mott insulator states of electrons forming a frustrated triangular lattice and observed direct evidence of magnetic correlations originating from a kinetic mechanism. By directly measuring electronic magnetization they found that when the Mott state was electron-doped, the system exhibited ferromagnetic correlations in agreement with the Nagaoka mechanism… read […]
Whole-infrared-band camouflage with dual-band radiative heat dissipation
Phys.org February 7, 2024 Achieving effective camouflage and thermal management across the entire infrared spectrum, especially the short-wave infrared (SWIR) band, remains challenging. Researchers in China proposed a multilayer wavelength-selective emitter that achieves effective camouflage across the entire infrared spectrum, including the near-infrared (NIR), SWIR, mid-wave infrared (MWIR), and long-wave infrared (LWIR) bands, as well as the visible (VIS) band. The emitter would enable radiative heat dissipation in two non-atmospheric windows. The emitter’s properties were characterized by low emittance in the SWIR/MWIR/LWIR bands, and low reflectance in the VIS/NIR bands. The high emittance in the two non-atmospheric windows would ensure […]
Top 10 Science and Technology Inventions for the Week of February 02, 2024
01. A physical qubit with built-in error correction 02. First tetratomic supermolecules realized at nanokelvin temperatures 03. A new wavelength of scientific exploration with single-photon detectors 04. New research shows how light propagates in integrated circuits on chips 05. Oxidation-induced super-elasticity in metallic glass nanotubes 06. Scientists make breakthrough in quantum materials research 07. Researchers add a ‘twist’ to classical material design 08. New method flips the script on topological physics 09. Tracking unconventional superconductivity 10. A type of plastic that can be shape-shifted using tempering And others Dipole-dipole interactions: Observing a new clock systematic shift Increased temperature difference between […]
Dipole-dipole interactions: Observing a new clock systematic shift
Phys.org January 27, 2024 Collective couplings of atomic dipoles to a shared electromagnetic environment produce a wide range of many-body phenomena. A team of researchers in the USA (University of Colorado, Colorado State University) reported on the direct observation of resonant electric dipole-dipole interactions in a cubic array of atoms in the many-excitation limit. The interactions produced spatially dependent cooperative Lamb shifts when spectroscopically interrogating the millihertz-wide optical clock transition in strontium-87. They showed that the ensemble-averaged shifts could be suppressed below the level of evaluated systematic uncertainties for optical atomic clocks. They demonstrated that excitation of the atomic dipoles […]
First tetratomic supermolecules realized at nanokelvin temperatures
Phys. org January 31, 2024 Ultracold polyatomic molecules offer opportunities in cold chemistry, precision measurements and quantum information processing because of their rich internal structure. However, their increased complexity compared with diatomic molecules presents a challenge in using conventional cooling techniques. An international team of researchers (Germany, China) demonstrated an approach to create weakly bound ultracold polyatomic molecules by electroassociation in a degenerate Fermi gas of microwave-dressed polar molecules through a field-linked resonance. They created around weakly bound tetratomic (NaK)2 molecules more than 3,000 times colder than previously realized tetratomic molecules. They observed a maximum tetramer lifetime of 8(2)?ms in […]
Increased temperature difference between day and night could affect all life on Earth, say scientists
Phys.org February 1, 2024 In the latter half of the twentieth century, a significant climate phenomenon “diurnal asymmetric warming” emerged, wherein global land surface temperatures increased more rapidly during the night than during the day. Recent episodes of global brightening and regional droughts and heatwaves have brought notable alterations to this asymmetric warming trend. An international team of researchers (Sweden, China) re-evaluated sub-diurnal temperature patterns, and revealed a substantial increase in the warming rates of daily maximum temperatures (Tmax) while daily minimum temperatures have remained relatively stable. This shift has resulted in a reversal of the diurnal warming trend, expanding […]
New method flips the script on topological physics
Science Daily January 25, 2024 The concept of topological phases is rather abstract, and the characterization of the spectral topology of mechanical structures has intrinsically relied on the a priori knowledge of idealized theoretical models. An international team of researchers (USA – University of Pennsylvania, the Netherlands, France) introduced and validated an experimental method to detect the topologically protected zero modes of mechanical structures without resorting to any modeling step. The method is based on a simple electrostatic analogy: Topological zero modes are akin to electric charges. To detect them, they identified elementary mechanical molecules and measured their chiral polarization. […]
New research shows how light propagates in integrated circuits on chips
Phys.org January 31, 2024 While the geometry of photonic integrated circuits can be characterized by existing means, their optimal and accurate performance requires detailed characterization of the light propagating within them. Researchers in Israel demonstrated the direct visualization of the light as it travels inside photonic integrated circuits. They used the natural nonlinear optical properties of silicon to directly map the electric field of the waves guided inside the integrated circuits, characterized waveguides and multimode splitters while extracting various parameters of the device. According to the researchers their work may be crucial component for the characterization of photonic circuitry, design […]
A new wavelength of scientific exploration with single-photon detectors
Phys.org January 31, 2024 Superconducting nanowire single-photon detectors (SNSPDs) are a mature photon-counting technology as demonstrated by their figures of merit such as high detection efficiencies and very low dark count rates. However, scaling SNSPDs to large array sizes for mid-infrared applications requires sophisticated readout architectures in addition to superconducting materials development. Researchers at NIST, Boulder, Colorado, developed an SNSPD array design that combined a thermally coupled row-column multiplexing architecture with a thermally coupled time-of-flight transmission line for mid-infrared applications. It required only six cables and could be scaled to larger array sizes. The demonstration of a 64-pixel array showed […]
Oxidation-induced super-elasticity in metallic glass nanotubes
Nanowerk February 2, 2024 Although metallic nanostructures are interesting for nanoscience and nanotechnologies, environmental attacks on them can easily initiate cracking on the surface of metals deteriorating their overall functional/structural properties. An international team of researchers (China, Hong Kong, Taiwan) shown that severely oxidized metallic glass nanotubes can attain an ultrahigh recoverable elastic strain at room temperature. They showed that the physical mechanisms underpinning the observed superelasticity could be attributed to the formation of a percolating oxide network in metallic glass nanotubes, which not only restricts atomic-scale plastic events during loading but also leads to the recovery of elastic rigidity […]