Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics – Page 274

A team of researchers at the University of Vienna, the Austrian Academy of Sciences and the University of Duisburg-Essen have found a new mechanism that fundamentally alters the interaction between optically levitated nanoparticles. Their experiment demonstrates previously unattainable levels of control over the coupling in arrays of particles, thereby creating a new platform to study complex physical phenomena. The results are published in this week’s issue of Science.

Imagine randomly floating around in the room. When a laser is switched on, the particles will experience forces of light and once a particle comes too close it will be trapped in the focus of the beam. This is the basis of Arthur Ashkin’s pioneering Nobel prize work of optical tweezers. When two or more particles are in the vicinity, light can be reflected back and forth between them to form standing waves of light, in which the particles self-align like a crystal of particles bound by light. This phenomenon, also called optical binding, has been known and studied for more than 30 years.

It came as quite a surprise to the researchers in Vienna when they saw a completely different behavior than was expected when studying forces between two glass nanoparticles. Not only could they change the strength and the sign of the binding force, but they could even see one particle, say the left, acting on the other, the right, without the right acting back on the left. What seems like a violation of Newton’s third law (everything that is being acted upon acts back with same strength but opposite sign) is so-called non-reciprocal behavior and occurs in situations in which a system can lose energy to its environment, in this case the laser. Something was obviously missing from our current theory of optical binding.

Read more | >

The team even transmitted video games through the atoms to a monitor.

Scientists at the US National Institute of Standards have developed an ‘Atomic Television’ that uses lasers and atom clouds to pick up video transmissions that meet the 480i resolution standard. The team demonstrated the same by transmitting live video feeds and even video games through the atoms to a monitor.

NIST

Continue reading “Researchers create ‘atomic television’ that transmits live video with big atoms and small lasers” | >

This will be very useful in progressing the field of quantum computers and communication.

Researchers at the Max Planck Institute of Quantum Optics set a new record after achieving a quantum entanglement of 14 photons, the largest on record so far, an institutional press release said.

Quantum entanglement, famously described by Albery Einstein as “spooky action at a distance” is a phenomenon where particles become intertwined in such a way that they cease to exist individually, and changing the specific property of one results in an instant change of its partner, even if it is far away.

Physicists at the Max Planck Institute of Quantum Optics have managed to entangle more than a dozen photons efficiently and in a defined way. They are thus creating a basis for a new type of quantum computer.

Continue reading “Entangled photons tailor-made” | >

Max Planck of Quantum Optics.

Quantum entanglement, famously described by Albery Einstein as “spooky action at a distance” is a phenomenon where particles become intertwined in such a way that they cease to exist individually, and changing the specific property of one results in an instant change of its partner, even if it is far away.

Read more | >

Cutting intricate patterns as small as several billionths of a meter deep and wide, the focused ion beam (FIB) is an essential tool for deconstructing and imaging tiny industrial parts to ensure they were fabricated correctly. When a beam of ions, typically of the heavy metal gallium, bombards the material to be machined, the ions eject atoms from the surface—a process known as milling—to sculpt the workpiece.

Beyond its traditional uses in the semiconductor industry, the FIB has also become a critical tool for fabricating prototypes of complex three-dimensional devices, ranging from lenses that focus light to conduits that channel fluid. Researchers also use the FIB to dissect biological and material samples to image their internal structure.

However, the FIB process has been limited by a trade-off between high speed and fine resolution. On the one hand, increasing the ion current allows a FIB to cut into the workpiece deeper and faster. On the other hand, the increased current carries a larger number of positively charged ions, which electrically repel each other and defocus the beam. A larger, diffuse beam, which can be about 100 nanometers in diameter or 10 times wider than a typical narrow beam, not only limits the ability to fabricate fine patterns but can also damage the workpiece at the perimeter of the milled region. As a result, the FIB has not been the process of choice for those trying to machine many tiny parts in a hurry.

Read more | >

The flow of time from the past to the future is a central feature of how we experience the world. But precisely how this phenomenon, known as the arrow of time, arises from the microscopic interactions among particles and cells is a mystery—one that researchers at the CUNY Graduate Center Initiative for the Theoretical Sciences (ITS) are helping to unravel with the publication of a new paper in the journal Physical Review Letters. The findings could have important implications in a variety of disciplines, including physics, neuroscience, and biology.

Fundamentally, the of arises from the second law of thermodynamics: the principle that microscopic arrangements of physical systems tend to increase in randomness, moving from order to disorder. The more disordered a system becomes, the more difficult it is for it to find its way back to an ordered state, and the stronger the arrow of time. In short, the universe’s tendency toward disorder is the fundamental reason why we experience time flowing in one direction.

“The two questions our team had were, if we looked at a particular system, would we be able to quantify the strength of its arrow of time, and would we be able to sort out how it emerges from the micro scale, where cells and interact, to the whole system?” said Christopher Lynn, the paper’s first author and a postdoctoral fellow with the ITS program. “Our findings provide the first step toward understanding how the arrow of time that we experience in emerges from these more microscopic details.”

Read more | >

Scientists have developed an ‘atomic television’ that uses lasers and atom clouds to carry a video signal that meets the traditional 480i resolution (480 horizontal lines) standard.

Just don’t expect it to be installed as part of your home entertainment setup any time soon.

Key to the technology is a glass container of gaseous super-sized rubidium atoms excited by two colors of laser beams into what’s known as a Rydberg state – that’s when atoms have a high level of energy, causing the electrons to orbit further out from the nucleus.

Read more | >

Getting atoms to do what you want isn’t easy – but it’s at the heart of a lot of groundbreaking research in physics.

Creating and controlling the behavior of new forms of matter is of particular interest and an active area of research.

Our new study, published in Physical Review Letters, has uncovered a brand new way of sculpting ultracold atoms into different shapes using laser light.

Read more | >

Physicists from TU Delft, ETH Zürich and the University of Tübingen have built a quantum scale heat pump made from particles of light. This device brings scientists closer to the quantum limit of measuring radio frequency signals, which may be useful in the hunt for dark matter. Their work will be published as an open-access article in Science Advances on Aug. 26.

If you bring two objects of different temperature together, such as putting a warm bottle of white wine into a cold chill pack, heat usually flows in one direction, from hot (the wine) to cold (the chill pack). And if you wait long enough, the two will both reach the same temperature, a process known in physics as reaching equilibrium: a balance between the heat flow one way and the other.

If you are willing to do some work, you can break this balance and cause heat to flow in the “wrong” way. This is the principle used in your refrigerator to keep your food cold, and in efficient heat pumps that can steal heat from the outside to warm your house. In their publication, Gary Steele and his co-authors demonstrate a quantum analog of a heat pump, causing the elementary quantum particles of light, known as , to move “against the flow” from a hot object to a cold one.

Read more | >

Two-dimensional materials, which consist of a single layer of atoms, exhibit unusual properties that could be harnessed for a wide range of quantum and microelectronics systems. But what makes them truly special are their flaws.

“That’s where their true magic lies,” said Alexander Weber-Bargioni at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

Defects down to the atomic level can influence the material’s macroscopic function and lead to novel quantum behaviors, and there are so many kinds of defects that researchers have barely begun to understand the possibilities. One of the biggest challenges in the field is systematically studying these defects at relevant scales, or with atomic resolution.

Read more | >