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Category: quantum physics – Page 12

🌌 Unifying AI Through the Feynman Path Integral: From Deep Learning to Quantum AI I’m pleased to share a framework that brings many areas of AI into a single mathematical structure inspired by the Feynman path integral —

🌌 Unifying AI Through the Feynman Path Integral: From Deep Learning to Quantum AI https://lnkd.in/g4Cfv6qd I’m pleased to share a framework that brings many areas of AI into a single mathematical structure inspired by the Feynman path integral — a foundational idea in quantum physics. Instead of viewing supervised learning, reinforcement learning, generative models, and quantum machine learning as separate disciplines, this framework shows that they all follow the same underlying principle: Learning is a weighted sum over possible solutions (paths), based on how well each one explains the data. In other words, AI can be viewed the same way Feynman viewed physics: as summing over all possible configurations, weighted by an action functional.

Photoinduced non-reciprocal magnetism effectively violates Newton’s third law

A theoretical framework predicts the emergence of non-reciprocal interactions that effectively violate Newton’s third law in solids using light, report researchers from Japan. They demonstrate that by irradiating light of a carefully tuned frequency onto a magnetic metal, one can induce a torque that drives two magnetic layers into a spontaneous, persistent “chase-and-run” rotation. This work opens a new frontier in non-equilibrium materials science and suggests novel applications in light-controlled quantum materials.

In equilibrium, obey the law of action and reaction as per the free energy minimization principle. However, in non-equilibrium systems such as biological or active matter—interactions that effectively violate this law—the so-called non-reciprocal interactions are common.

For instance, the brain comprises inhibitory and excitatory neurons that interact non-reciprocally; the interaction between predator and prey is asymmetric, and colloids immersed in an optically active media demonstrate non-reciprocal interactions as well. A natural question arises: Can one implement such non-reciprocal interaction in solid-state electronic systems?

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.

Startup provides a nontechnical gateway to coding on quantum computers

Quantum computers have the potential to model new molecules and weather patterns better than any computer today. They may also one day accelerate artificial intelligence algorithms at a much lower energy footprint. But anyone interested in using quantum computers faces a steep learning curve that starts with getting access to quantum devices and then figuring out one of the many quantum software programs on the market.

Now qBraid, founded by Kanav Setia and Jason Necaise ‘20, is providing a gateway to quantum computing with a platform that gives users access to the leading and software. Users can log on to qBraid’s cloud-based interface and connect with quantum devices and other computing resources from leading companies like Nvidia, Microsoft, and IBM. In a few clicks, they can start coding or deploy cutting-edge software that works across devices.

“The mission is to take you from not knowing anything about quantum computing to running your first program on these amazing machines in less than 10 minutes,” Setia says. “We’re a one-stop platform that gives access to everything the quantum ecosystem has to offer. Our goal is to enable anyone—whether they’re enterprise customers, academics, or individual users—to build and ultimately deploy applications.”

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 .

New Quantum Battery Could Revolutionize Energy Storage

Scientists have designed a topological quantum battery that can charge efficiently without losing energy, using the unique properties of quantum mechanics and topology.

Their research suggests dissipation, long considered harmful, might actually boost power in these next-generation batteries.

Quantum Leap in Energy Storage.

Engineers achieve record 31% efficiency in red quantum LEDs for enhanced display color and brightness

A research team led by the School of Engineering of The Hong Kong University of Science and Technology (HKUST) has made significant advances in quantum rod light-emitting diodes (QR-LEDs), setting record-high efficiency level for red QR-LEDs. This innovation is poised to revolutionize next-generation display and lighting technologies, offering smartphone and television users a vibrant and enhanced visual experience. The research is published in the journal Advanced Materials.

LEDs have been widely used in for decades. Recent developments in have given rise to quantum dot LEDs (QD-LEDs) and QR-LEDs. QD-LEDs offer superior color purity (color vividness) and higher brightness compared to current mainstream LEDs. However, outcoupling efficiency has now become the primary obstacle, as it sets a fundamental ceiling for external quantum efficiency (EQE), thereby hindering any further performance improvements.

Quantum rods, on which QR-LEDs are based, are a type of elongated anisotropic nanocrystals with unique optical properties that can be engineered to optimize the light emission direction and ultimately improve outcoupling efficiency. However, QR-LEDs encounter two significant technical challenges: first, the ratio of emitted to absorbed photons (photoluminescence quantum yield) is relatively low after the material absorbs photons; second, there is a substantial leakage current due to poor thin-film quality.

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