Phys.org January 12, 2023 Room temperature polariton condensate lattices, suitable candidates for neuromorphic computing and physical simulations of complex problems, have been achieved by nanoimprinting microcavities, which by nature lacks the crucial tunability required for realistic reconfigurable simulators. An international team of researchers (UK, Singapore) has made a quantum harmonic oscillator at room temperature by an on-the-fly fully tunable optical approach. The condensate is delocalised from the excitation region by macroscopic distances, leading both to longer coherence and a threshold one order of magnitude lower than that with a conventional Gaussian excitation profile. They observed different mode selection behaviour compared […]
Scientists sound alarm as ocean temperatures hit new record
Phys.org January 11, 2023 In 2022, the world’s oceans, as given by changes in ocean heat content (OHC), were again the hottest in the historical record and exceeded the previous 2021 record maximum due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. An international team of researchers (China, USA – University of St. Thomas, NCAR, NOAA, University of Pennsylvania, University of Maryland, New Zealand, Italy) recorded the highest OHC since the 1950s among seven regions, four basins (the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans). […]
‘Smart’ coating can be precisely applied to make fabric into protective gear
Science Daily January 9, 2023 Previously a team of researchers in the US (Dartmouth University, Maine University, DEVCOM Aberdeen Proving Ground) had developed conductive metal-organic technology (framework) which was a simple coating that could be layered onto cotton and polyester to create smart fabrics. In their current work, instead of the simple coating they precisely embedded the framework into fabrics using a copper precursor that allowed them to create specific patterns and more effectively fill in the tiny gaps and holes between threads. They found that the framework technology effectively converted the toxin nitric oxide into nitrite and nitrate, and […]
Supercomputer simulations transform coal-like material to amorphous graphite and nanotubes
Nanowerk January 6, 2023 To explore how coal can be converted into valuable materials like graphite researchers at Ohio University simulated the substances in computer software. They created a simplified “coal” that consisted of only carbon atoms in random position and exposed them to pressure and high temperature — about 3,000 Kelvin. They formed sheets, but the carbon atoms didn’t entirely develop simple, six-carbon rings. A fraction of the rings had five carbons; others had seven. While six-carbon rings were flat, five- and seven-membered carbon rings puckered. The conditions in these simulations caused the sheets to curve in on themselves […]
Top 10 Science and Technology Inventions for the Week of January 6, 2023
01. Chip circuit for light could be applied to quantum computations 02. Electronic bridge allows rapid energy sharing between semiconductors 03. High-performance visible-light lasers that fit on a fingertip 04. High-visibility quantum interference between two independent semiconductor quantum dots achieved 05. Physicists Discover a New Way to ‘See’ Objects Without Looking at Them 06. Researchers develop a light source that produces two entangled light beams 07. Researchers discover new process to create freestanding membranes of ‘smart’ materials 08. Scientists develop a cool new method of refrigeration 09. Self-repairing healing solar cells recovering in the dark of the night 10. A […]
Chip circuit for light could be applied to quantum computations
Phys.org January 3, 2023 While substantial progress has been made, separately, towards ultra-low loss chip-scale photonic circuits and high brightness single-photon sources, integration of these technologies has remained elusive. An international team of researchers (USA – National Institute of Standards and Technology, University of Maryland, research org., MIT, UC Santa Barbara, industry, Brazil, South Korea) integrated a quantum emitter single-photon source with a wafer-scale, ultra-low loss silicon nitride photonic circuit to demonstrate triggered and pure single-photon emission into a Si3N4 photonic circuit with ≈ 1 dB/m propagation loss at a wavelength of ≈ 930 nm. They observed resonance fluorescence in the strong drive regime, showing promise […]
Electronic bridge allows rapid energy sharing between semiconductors
Phys. org January 4, 2023 A team of researchers in the US (SLAC National Accelerator Laboratory, Stanford University, UC Berkeley) studied devices consisting of stacked monolayers of WSe2 and WS2. They found that the WSe2 layer heated up, as expected, and the WS2 layer also heated up in tandem, suggesting a rapid transfer of heat between layers. By contrast, when they didn’t excite electrons in the WSe2 and heated the heterostructure using a metal contact layer instead, the interface between WSe2 and WS2 transmitted heat very poorly, confirming previous reports. It was surprising to see the two layers heat up […]
High-performance visible-light lasers that fit on a fingertip
Phys.org January 4, 2023 Widely tunable and narrow-linewidth lasers at visible wavelengths are necessary for applications such as quantum optics, optical clocks, and atomic and molecular physics. At present, the lasers are benchtop systems, which precludes these technologies from being used outside research laboratories. A team of researchers in the US (Columbia University, Tufts University) has demonstrated a chip-scale visible laser platform that enables tunable and narrow-linewidth lasers from near-ultraviolet to near-infrared wavelengths. Using micrometre-scale silicon nitride resonators and commercial Fabry–Pérot laser diodes, they achieved coarse tuning up to 12.5 nm and mode-hop-free fine tuning up to 33.9 GHz with intrinsic linewidths […]
High-visibility quantum interference between two independent semiconductor quantum dots achieved
Phys.org December 28, 2022 There has been exciting recent progress in satellite-based quantum communications and quantum repeaters, but a lack of suitable single-photon sources has hampered further advances. The visibility of quantum interference between independent QDs rarely went beyond the classical limit of 50%, and the distances were limited from a few meters to kilometers. An international team of researchers (China, Germany) has shown quantum interference between two single photons from independent QDs separated by a 302 km optical fiber. The single photons were generated from resonantly driven single QDs deterministically coupled to microcavities. Quantum frequency conversions were used to […]
Physicists Discover a New Way to ‘See’ Objects Without Looking at Them
Science Alert December 29, 2022 Instead of lasers and mirrors, researchers in Finland proposed the concept of coherent interaction-free detection and demonstrated it experimentally using a three-level superconducting transmon circuit to detect an electromagnetic wave pulsed into a chamber. They showed that it is possible to ascertain the presence of a microwave pulse resonant with the second transition of the transmon, while at the same time avoid exciting the device onto the third level. Experimentally, this was done by using a series of Ramsey microwave pulses coupled into the first transition and monitoring the ground-state population. The protocol can be […]