Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: computing – Page 75

A new atomistic route to viscosity—even near the glass transition

We rarely think about how liquids flow—why honey is thick, water is thin or how molten plastic moves through machines. But for scientists and engineers, understanding and predicting the viscosity of materials, especially polymers, is essential.

Viscosity governs how substances deform and flow under stress, which in turn affects how they are processed, how they behave in industrial pipelines, in environmental settings, or in consumer products, and how they respond to changing temperatures.

Traditionally, to calculate the of a liquid or polymer melt based on molecular simulations on computers, people rely on a method called the Green–Kubo formalism. It works by tracking how internal stresses fluctuate and decay over time inside a simulated material at thermodynamic equilibrium.

‘ALS on a chip’ model reveals altered motor neuron signaling

Using stem cells from patients with ALS (amyotrophic lateral sclerosis), Cedars-Sinai has created a lifelike model of the mysterious and fatal disease that could help identify a cause of the illness as well as effective treatments.

In a study published in the journal Cell Stem Cell, investigators detail how they created “ALS on a chip” and the clues the specialized laboratory chip has already produced about nongenetic causes of the disease, also known as Lou Gehrig’s disease.

The work builds on previous studies where adult cells from ALS patients were reverted into . The cells were then pushed forward to produce motor neurons, which die in the disease, causing progressive loss of the ability to move, speak, eat and breathe.

Researchers confirm fundamental conservation laws at the quantum level

Researchers at Tampere University and their collaborators from Germany and India have experimentally confirmed that angular momentum is conserved when a single photon is converted into a pair – validating a key principle of physics at the quantum level for the first time. This breakthrough opens new possibilities for creating complex quantum states useful in computing, communication, and sensing.

Conservation laws are the heart of our natural scientific understanding as they govern which processes are allowed or forbidden. A simple example is that of colliding billiard balls, where the motion – and with it, their linear momentum – is transferred from one ball to another. A similar conservation rule also exists for rotating objects, which have angular momentum. Interestingly, light can also have an angular momentum, e.g., orbital angular momentum (OAM), which is connected to the light’s spatial structure.

In the quantum realm, this implies that single particles of light, so-called photons, have well-defined quanta of OAM, which need to be conserved in light-matter interactions. In a recent study in Physical Review Letters, researchers from Tampere University and their collaborators, have now pushed the test of these conservation laws to absolute quantum limit. They explore if the conservation of OAM quanta holds when a single photon is split into a photon pair.

Quantum breakthrough: ‘Magic states’ now easier, faster, and way less noisy

Quantum computing just got a significant boost thanks to researchers at the University of Osaka, who developed a much more efficient way to create “magic states”—a key component for fault-tolerant quantum computers. By pioneering a low-level, or “level-zero,” distillation method, they dramatically reduced the number of qubits and computational resources needed, overcoming one of the biggest obstacles: quantum noise. This innovation could accelerate the arrival of powerful quantum machines capable of revolutionizing industries from finance to biotech.

Physicists confirm elusive quantum spin liquid in new study

An international team of scientists led by Rice University’s Pengcheng Dai has confirmed the existence of emergent photons and fractionalized spin excitations in a rare quantum spin liquid. Published in Nature Physics on June 19, their findings identify the crystalline compound cerium zirconium oxide (Ce₂Zr₂O₇) as a clear 3D realization of this exotic state of matter.

Long a subject of theoretical intrigue, quantum spin liquids offer promise for revolutionary technologies, including and dissipationless energy transmission. By refusing to conform to traditional magnetic behavior, these materials realize emergent quantum electrodynamics via highly quantum-entangled motions of magnetic moments at temperatures near absolute zero.

“We’ve answered a major open question by directly detecting these excitations,” said Dai, the Sam and Helen Worden Professor of Physics and Astronomy. “This confirms that Ce₂Zr₂O₇ behaves as a true quantum spin ice, a special class of quantum spin liquids in three dimensions.”

Near-perfect defects in 2D material could serve as quantum bits

Scientists across the world are working to make quantum technologies viable at scale—an achievement that requires a reliable way to generate qubits, or quantum bits, which are the fundamental units of information in quantum computing.

The task has so far remained elusive, but one of the materials that has garnered a lot of attention as a possible qubit platform is (h-BN), a 2D material that can host solid-state single-photon emitters (SPEs). Like the name indicates, SPEs are atomic structures in solid materials that can produce individual photons.

In a new study published in Science Advances, researchers at Rice University and collaborators at Oak Ridge National Laboratory and the University of Technology, Sydney report the first demonstration of low noise, room-temperature quantum emitters in h-BN made through a scalable growth technique.

/* */