Phys.org February 10, 2023 Satellite-based quantum links have been proposed to extend the network domain for quantum communication. An international team of researchers (USA – Oak Ridge National Laboratory, University of Illinois, Singapore) developed a quantum communication system, suitable for realistic satellite-to-ground communication and executed an entanglement-based quantum key distribution (QKD) protocol achieving quantum bit-error rates (QBERs) below 2% in all bases. They demonstrated low-QBER execution of a higher-dimensional hyperentanglement-based QKD protocol, using photons simultaneously entangled in polarization and time bin, leading to significantly higher secure key rates, at the cost of increased technical complexity and system size. They showed […]
Scientists boost quantum signals while reducing noise
MIT News February 9, 2023 Squeezing of the electromagnetic vacuum is an essential metrological technique used to reduce quantum noise in applications spanning gravitational wave detection, biological microscopy and quantum information science. In superconducting circuits, the resonator-based Josephson-junction parametric amplifiers conventionally used to generate squeezed microwaves are constrained by a narrow bandwidth and low dynamic range. An international team of researchers (USA – MIT, MIT Lincoln Laboratory, industry, Australia) developed a dual-pump, broadband Josephson travelling-wave parametric amplifier that combined a phase-sensitive extinction ratio of 56 dB with single-mode squeezing on par with the best resonator-based squeezers. They demonstrated two-mode squeezing at […]
Scientists can now map lightning in 3D
Phys.org February 15, 2023 A team of researchers in the US (Los Alamos National Laboratory, New Mexico Institute of Mining and Technology) developed and deployed a new 3-dimensional broadband radio frequency interferometric mapping and polarization system (BIMAP-3D) which provides an unprecedented capability in high-resolution, time-evolving 3D lightning source mapping and 3D source polarization detection for detailed study of lightning discharge physics. In this article they described the BIMAP-3D system design, a generalized and analytical 2D interferometry technique for noncoplanar antenna array, a two-stage 3D mapping technique based on geometric triangulation and baseline-based differential time of arrival, and a technique to […]
When the light is neither ‘on’ nor ‘off’ in the nanoworld
Phys.org February 14, 2023 Plasmon modes are treated as quasiparticles, and they are considered essential for the realization of future nanoscale quantum functionality. Implementing and demonstrating such functionality requires access to the quasiparticle’s quantum state to monitor and manipulate its corresponding quantum wave packet dynamics in Hilbert space. Researchers in Germany succeeded in detecting such superposition states of light directly in a nanostructure using plasmon-assisted electron emission as a signal in coherent two-dimensional nanoscopy. The observation of a quantum coherence oscillating at the third harmonic of the plasmon frequency was traced back to the superposition of energetically non-adjacent plasmon occupation […]
Top 10 Science and Technology Inventions for the week of February 10, 2023
Distortion-free structured light Entangled atoms cross quantum network from one lab to another The first lab-created ‘quantum abacus’ New crystal growth orientation method manipulates properties of materials New ice is like a snapshot of liquid water New sodium, aluminum battery aims to integrate renewables for grid resiliency Researchers devise a new path toward ‘quantum light’ A quasiparticle that can transfer heat under electrical control Scientists open new window on the physics of glass formation Scientists realize faster method for quantum key distribution And others Ice cores show even dormant volcanoes leak abundant sulfur into the atmosphere Major publishers are banning […]
Distortion-free structured light
Phys.org February 7, 2023 Both real-world and experimentally simulated turbulence conditions have revealed that free-space structured light modes are perturbed by turbulence resulting in both amplitude and phase distortions, and consequently, much attention has focused on whether one mode type is more robust than another, but with inconclusive and contradictory results. Researchers in South Africa have shown complex forms of structured light that are invariant under propagation through the atmosphere: the true eigenmodes of atmospheric turbulence. They provided a theoretical procedure for obtaining these eigenmodes and confirmed their invariance both numerically and experimentally. According to the researchers although they have […]
Entangled atoms cross quantum network from one lab to another
Science Daily February 2, 2023 Trapped ions are one of the leading systems to build quantum computers and other quantum technologies. To link multiple such quantum systems, interfaces are needed through which the quantum information can be transmitted. An international team of researchers (Austria, USA – Georgetown University, Switzerland, France) has demonstrated an elementary quantum network of two atomic ions separated by 230 m. The ions were trapped in different buildings and connected with 520(2) m of optical fiber. At each network node, the electronic state of an ion was entangled with the polarization state of a single cavity photon; […]
The first lab-created ‘quantum abacus’
Phys.org February 2, 2023 An international team of researchers (UK, Italy) has reported the experimental realization of the prime number quantum potential VN(x), defined as the potential entering the single-particle Schrödinger Hamiltonian with eigenvalues given by the first N prime numbers. Using computer-generated holography, they created light intensity profiles suitable to optically trap ultracold atoms in these potentials for different N values. As a further application, they implemented a potential whose spectrum is given by the lucky numbers, a sequence of integers generated by a different sieve than the familiar Eratosthenes’s sieve used for the primes. According to the researchers their results pave the way […]
Ice cores show even dormant volcanoes leak abundant sulfur into the atmosphere
Phys.org February 3, 2023 Sulfate aerosols are particles in the atmosphere that have a net cooling effect on the climate. One of the most uncertain aspects of climate modeling is the abundance of sulfate aerosols during the preindustrial era. Without knowing the amount of sulfate aerosols during the preindustrial times, it is difficult to estimate how much anthropogenic sulfate aerosols have offset warming from anthropogenic greenhouse gases. A team of researchers in the US (University of Washington, South Dakota State University, University of New Mexico, Michigan Technological University) examined preindustrial sulfate aerosols in a Greenland ice core. They found that […]
Major publishers are banning ChatGPT from being listed as an academic author. What’s the big deal?
Phys.org January 31, 2023 Several papers published recently have listed ChatGPT as an author. Last week, both the Science and Nature journals declared their positions on the use of ChatGPT to generate articles. Science is updating its license and editorial policies to “specify that text generated by ChatGPT (or any other AI tools) cannot be used in the work, nor can figures, images, or graphics be the products of such tools”. Similarly, Nature has formulated the following principles: “No LLM (large language model) tool will be accepted as a credited author on a research paper… Researchers using LLM tools should […]