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Category: computing – Page 5

Scientists reveal it is feasible to send quantum signals from Earth to a satellite

Quantum satellites currently beam entangled particles of light from space down to different ground stations for ultra-secure communications. New research shows it is also possible to send these signals upward, from Earth to a satellite; something once thought unfeasible.

This breakthrough overcomes significant barriers to current quantum communications. Ground station transmitters can access more power, are easier to maintain and could generate far stronger signals, enabling future quantum computer networks using satellite relays.

The study, “Quantum entanglement distribution via uplink satellite channels”, by Professor Simon Devitt, Professor Alexander Solntsev and a research team from the University of Technology Sydney (UTS), is published in the journal Physical Review Research.

“We Made the World’s Best Material” — How a Diamond Substitute Could Revolutionize Quantum Computing

Strontium titanate’s remarkable ability to perform at extremely low temperatures makes it a key material for next-generation cryogenic devices used in quantum computing and space exploration. Superconductivity and quantum computing have moved beyond theoretical research to capture the public’s im

Stellar Giants Forged the Chemical Diversity of Ancient Clusters

“Extremely massive stars may have played a key role in the formation of the first galaxies,” said Dr. Paolo Padoan.

How did the extremely massive stars (EMS) in the early universe help form the oldest star clusters? This is what a recent study published in the Monthly Notices of the Royal Astronomical Society hopes to address as an international team of scientists investigated the role that EMS played in not only forming globular clusters (GCs), but how the latter were responsible for forming the first black holes. This study has the potential to help scientists better understand the conditions of the early universe and what this could mean to better understanding our existence.

For the study, the researchers presented a new computational model to help explain how EMS contributed to GC formation with bodies celestial objects being between 1,000 to 10,000 times as massive as our Sun and containing hundreds of thousands to millions of stars, respectively. Given the massive sizes and short lifetimes of EMS, they go supernova when they die, and the new model postulates they become black holes while releasing massive amounts of chemical and hydrogen that mixes with surrounding gas and dust, resulting in the formation of GCs. Additionally, data obtained from NASA’s James Webb Space Telescope (JWST) discovered nitrogen-rich galaxies had chemical signatures obtained from GCs.

Women perceive sleek and shiny hair as healthier and more youthful, study finds

Straight-aligned hair paired with higher shine evokes the appearance of greater youth, health, and attractiveness, according to researchers at The Procter & Gamble Company, which owns several brands of hair care products, including ones designed to make hair shinier.

Studies on appearance often center on facial shape and . Previous studies also note that skin topography and coloration can influence judgments of age, health, and attractiveness across populations. Facial studies often remove hair cues to avoid biasing feature focused framing of perception.

Hair holds social cues that observers can read quickly. Work with computer-rendered hair has tied diameter, density, style, and color to shifts in perceived age, health, and attractiveness, and some studies previously associated healthier-looking hair with the appearance of better reproductive health.

Light can reshape atom-thin semiconductors for next-generation optical devices

Rice University researchers studying a class of atom-thin semiconductors known as transition metal dichalcogenides (TMDs) have discovered that light can trigger a physical shift in their atomic lattice, creating a tunable way to adjust the materials’ behavior and properties.

The effect, observed in a TMD subtype named after the two-faced Roman god of transitions, Janus, could advance technologies that use light instead of electricity, from faster and cooler computer chips to ultrasensitive sensors and flexible optoelectronic devices.

“In , light can be reshaped to create new colors, faster pulses or optical switches that turn signals on and off,” said Kunyan Zhang, a Rice doctoral alumna who is a first author on a study documenting the effect. “Two-dimensional materials, which are only a few atoms thick, make it possible to build these optical tools on a very small scale.”

Optimizing avalanche photodiode design for photodetection in the ultraviolet wavelength

Geiger-mode avalanche photodiodes (GM-APDs) are highly sensitive light detectors, capable of detecting single photons. Photons of certain wavelengths, when absorbed by photodiodes, generate electron-hole pairs in a process called impact ionization which can result in a multiplication of charges when occurring in an electric field.

An avalanche photodiode is biased above its “,” at which point impact ionizations reach a self-sustaining rate, resulting in a distinct electrical pulse that is readily detectable. To detect in the presence of other mechanisms that generate impact ionization, the avalanche diode must simultaneously have a high probability to absorb incident photons of the desired wavelength, known as the unity-gain quantum efficiency (QE). Both being able to support high fields and having good QE at the desired wavelength are critical factors in determining the device’s sensitivity.

Certain GM-APDs based on 4H-silicon carbide (4H-SiC) have high single-photon detection efficiency in the deep-ultraviolet (DUV) wavelengths around 280 nanometers. To reliably detect photons at higher wavelengths where absorption is weaker, SiC GM-APDs need to improve their baseline photon capture efficiency, as indicated by its unity-gain QE. To accomplish this, researchers often employ APDs with much thicker absorber layers. However, this can often lead to design challenges.

Physicists achieve high precision in measuring strontium atoms using rubidium neighbor

Having good neighbors can be very valuable—even in the atomic world. A team of Amsterdam physicists was able to determine an important property of strontium atoms, a highly useful element for modern applications in atomic clocks and quantum computers, to unprecedented precision. To achieve this, they made clever use of a nearby cloud of rubidium atoms. The results were published in the journal Physical Review Letters this week.

Strontium. It is perhaps not the most popularly known chemical element, but among a group of physicists it has a much better reputation—and rightfully so.

Strontium is one of six so-called alkaline earth metals, meaning that it shares properties with better-known cousins like magnesium, calcium and radium. Strontium atoms have 38 protons in their nucleus, and a varying number of neutrons—for the variations (or isotopes) of strontium that can be found in nature, either 46, 48, 49 or 50.

Thin-film strontium titanate sets electro-optic performance record at cryogenic temperatures

At 4 degrees Kelvin, most electro-optic materials falter. Nanoelectronics R&D center imec has now successfully engineered thin-film strontium titanate (SrTiO₃) that delivers record electro-optic performance with low optical loss, pointing to shorter, faster building blocks for quantum devices.

Quantum computers and detectors run at temperatures close to absolute zero. In these , even the best room-temperature materials struggle to control light efficiently. This feature is essential to encode, route, and convert information in electro-optic networks, which at room temperature are used in data and telecom applications, but also increasingly for ultra-low temperature quantum links.

In a new paper published today in Science, imec researchers, in collaboration with KU Leuven and Ghent University, report how they re-engineered a common crystal, (SrTiO₃), so it behaves with record performance at .

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