Archive for the ‘quantum physics’ category: Page 12

Dec 9, 2023

A micro-ring resonator with big potential: Hybrid device significantly improves laser technology

Posted by in categories: computing, engineering, quantum physics

The team at EPFL’s Photonic Systems Laboratory (PHOSL) has developed a chip-scale laser source that enhances the performance of semiconductor lasers while enabling the generation of shorter wavelengths.

This pioneering work, led by Professor Camille Brès and postdoctoral researcher Marco Clementi from EPFL’s School of Engineering represents a significant advance in the field of photonics, with implications for telecommunications, metrology, and other high-precision applications.

The study, published in the journal Light: Science & Applications, reveals how the PHOSL researchers, in collaboration with the Laboratory of Photonics and Quantum Measurements, have successfully integrated semiconductor lasers with silicon nitride photonic circuits containing microresonators. This integration results in a hybrid device that emits highly uniform and precise light in both near-infrared and visible ranges, filling a technological gap that has long challenged the industry.

Dec 9, 2023

Diamond quantum sensors measure neuron activity

Posted by in categories: biotech/medical, neuroscience, quantum physics

A recent study by European scientists shows that highly sensitive sensors based on color centers in a diamond can be used to record electrical activity from neurons in living brain tissue. The work is published in the journal Scientific Reports.

Before people encounter symptoms of diseases such as dementia, slight changes have usually occurred already in the . It may be that parts of the brain are swelling up or clumps of proteins are forming. These small changes might influence how in the brain signal each other and communicate, how information is processed and memorized.

Medical scientists want to study these minor changes that occur in the very early stages of a disease. That way, the intention is to learn more about the causes of the disease to provide new insights and more efficient treatments. Today, microscopic studies on the brain are performed with one of two strategies: Optical inspection of brain tissue samples from animals or deceased patients that suffer from the studied disease or measurements of the signals from the nerve cells using wires, coloring, or light.

Dec 9, 2023

A superconducting junction made from a single 2D material promises to harness strange new physics

Posted by in categories: computing, engineering, particle physics, quantum physics

Physicists at RIKEN have developed an electronic device that hosts unusual states of matter, which could one day be useful for quantum computation.

When a material exists as an ultrathin layer—a mere one or a few atoms thick—it has totally different properties from thicker samples of the same material. That’s because confining electrons to a 2D plane gives rise to exotic states. Because of their flat dimensions and their broad compatibility with existing semiconductor technologies, such 2D materials are promising for harnessing new phenomenon in .

These states include quantum spin Hall insulators, which conduct electricity along their edges but are electrically insulating in their interiors. Such systems when coupled with superconductivity have been proposed as a route toward engineering topological superconducting states that have potential application in future topological quantum computers.

Dec 7, 2023

Magnetic Revolution: Diamonds and Rust Rewrite Physics Textbooks

Posted by in categories: computing, quantum physics

Cambridge researchers have identified magnetic monopoles in hematite, suggesting new possibilities for advanced, eco-friendly computing technologies. This first-time observation of emergent monopoles in a natural magnet could unlock new avenues in quantum material research.

Researchers have discovered magnetic monopoles – isolated magnetic charges – in a material closely related to rust, a result that could be used to power greener and faster computing technologies.

Researchers led by the University of Cambridge used a technique known as diamond quantum sensing to observe swirling textures and faint magnetic signals on the surface of hematite, a type of iron oxide.

Dec 7, 2023

Breakthrough in coherent two-photon LIDAR overcomes range limitations

Posted by in categories: innovation, quantum physics

New research has unveiled an advancement in Light Detection and Ranging (LIDAR) technology, offering unparalleled sensitivity and precision in measuring the distance of remote objects.

This research, published in Physical Review Letters, is a result of a collaboration between the group of Professor Yoon-Ho Kim at POSTECH in South Korea, and the Quantum Science and Technology Hub at the University of Portsmouth.

Coherent LIDAR has long been a cornerstone in distance measurement, but its capabilities have been restrained by the time of the light source. In a pioneering move, researchers have introduced two-photon LIDAR, eliminating the range limitations imposed by coherence time, to achieve accurate and precise ranging of a remote object situated far beyond the coherence time dictated by the spectral bandwidth of the light source.

Dec 7, 2023

IBM unveils new quantum computing chip to ‘explore new frontiers of science’

Posted by in categories: particle physics, quantum physics, robotics/AI, science

Computer and AI giant rolls out machine using ‘Heron’ chips using subatomic particles instead of ones and zeros.

Dec 7, 2023

Fractal photonic anomalous Floquet topological insulators to generate multiple quantum chiral edge states

Posted by in categories: evolution, quantum physics

An anomalous Floquet topological insulator (AFTI) is a periodically driven topological insulator (TI with nonzero winding numbers to support topological edge modes, though its standard topological invariants like Chern numbers are zero.

The photonic constructed by an optical array fabricated by the femtosecond laser direct writing (FLDW) is an important platform for to realize photonic AFTIs, because the FLDW offers flexible design of true three-dimensional (3D) waveguide structures and precise control of each coupling between waveguides. Moreover, the evolution distance of the lattice can be mapped as the evolution time.

In -direct-written photonic AFTIs, selective coupling of adjacent waveguides in a cycle is explicitly defined by the discrete periodically driving protocol. At the complete transfer discrete driving protocol, chiral edge modes co-exist with dispension-less bulk modes, and the lattice energy transfer efficiency of the chiral edge mode is the highest among all TIs (close to 100%), so it is very suitable for the transport of fragile quantum states.

Dec 7, 2023

Polaritons open up a new lane on the semiconductor highway

Posted by in categories: engineering, nanotechnology, particle physics, quantum physics

On the highway of heat transfer, thermal energy is moved by way of quantum particles called phonons. But at the nanoscale of today’s most cutting-edge semiconductors, those phonons don’t remove enough heat. That’s why Purdue University researchers are focused on opening a new nanoscale lane on the heat transfer highway by using hybrid quasiparticles called “polaritons.”

Thomas Beechem loves . He talks about it loud and proud, like a preacher at a big tent revival.

“We have several ways of describing energy,” said Beechem, associate professor of mechanical engineering. “When we talk about light, we describe it in terms of particles called ‘photons.’ Heat also carries energy in predictable ways, and we describe those waves of energy as ‘phonons.’ But sometimes, depending on the material, photons and phonons will come together and make something new called a ‘.’ It carries energy in its own way, distinct from both photons or phonons.”

Dec 7, 2023

Time’ May Explain Why Gravity Won’t Play by Quantum Rules

Posted by in categories: cosmology, particle physics, quantum physics

A new theory suggests that the unification between quantum physics and general relativity has eluded scientists for 100 years because huge “fluctuations” in space and time mean that gravity won’t play by quantum rules.

Since the early 20th century, two revolutionary theories have defined our fundamental understanding of the physics that governs the universe. Quantum physics describes the physics of the small, at scales tinier than the atom, telling us how fundamental particles like electrons and photons interact and are governed. General relativity, on the other hand, describes the universe at tremendous scales, telling us how planets move around stars, how stars can die and collapse to birth black holes, and how galaxies cluster together to build the largest structures in the cosmos.

Dec 7, 2023

Quantum ‘magic’ could help explain the origin of spacetime

Posted by in categories: cosmology, mathematics, particle physics, quantum physics

A quantum property dubbed “magic” could be the key to explaining how space and time emerged, a new mathematical analysis by three RIKEN physicists suggests. The research is published in the journal Physical Review D.

It’s hard to conceive of anything more basic than the fabric of spacetime that underpins the universe, but have been questioning this assumption. “Physicists have long been fascinated about the possibility that space and time are not fundamental, but rather are derived from something deeper,” says Kanato Goto of the RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS).

This notion received a boost in the 1990s, when theoretical physicist Juan Maldacena related the gravitational theory that governs spacetime to a theory involving . In particular, he imagined a hypothetical space—which can be pictured as being enclosed in something like an infinite soup can, or “bulk”—holding objects like that are acted on by gravity. Maldacena also imagined particles moving on the surface of the can, controlled by . He realized that mathematically a used to describe the particles on the boundary is equivalent to a gravitational theory describing the black holes and spacetime inside the bulk.

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