Lifeboat Foundation

Two teams demonstrate an innovative way to measure the states of spin-based qubits—a key task in quantum computing.

Researchers predict that the “scattering matrix” of a collection of particles could be used to slow the particles down, potentially allowing for the cooling of significantly more particles than is possible with current techniques.

When light travels through an environment containing many particles, information about the collective motion of the particles gets added to the light. This information leaves a measurable signature on a quantity known as the scattering matrix. Now researchers from the Vienna University of Technology predict that the information in this matrix could be used to alter the speeds of the particles [1, 2]. The team says that, if experimentally realized, the technique could allow scientists to study the collective quantum behavior of more particles than is possible with current techniques.

Researchers have long been fascinated with using light to slow down or even freeze the motion of a collection of particles. One motivation is that cooled particles can be isolated from outside influences in order to study quantum behaviors such as entanglement. To date, researchers have simultaneously cooled one or two particles, but they have struggled to scale techniques to cool additional particles.

Quantum entanglement refers to a phenomenon in quantum mechanics in which two or more particles become linked such that the state of each particle cannot be described independently of the others, even when they are separated by a large distance. The principle, referred to by Albert Einstein as “spooky action at a distance,” is now utilized in quantum networks to transfer information. The building blocks of these networks—quantum nodes—can generate and measure quantum states.

Among the candidates that can function as quantum nodes, the Sn-V center in diamond (a defect where a tin (Sn) atom replaces a carbon atom, resulting in an interstitial Sn atom between two carbon vacancies) has been shown to have suitable properties for quantum network applications.

The Sn-V center is expected to exhibit a long spin coherence time in the millisecond range at Kelvin temperatures, allowing it to maintain its quantum state for a relatively long period of time. However, these centers have yet to produce photons with similar characteristics, which is a necessary criterion for creating remote entangled quantum states between quantum network nodes.

The Laboratoire Sous-marin Provence Méditerranée (LSPM) lies 40 km off the coast of Toulon, at a depth of 2,450 m, inaccessible even to sunlight. Through this national research platform run by the CNRS in collaboration with Aix-Marseille University (AMU) and IFREMER, scientists will investigate undersea unknowns while scanning the skies for neutrinos. These elementary particles of extraterrestrial origin know few obstacles and can even traverse our planet without bumping into a single atom.

The main instrument at the LSPM is KM3NeT, a giant neutrino detector developed by a team of 250 researchers from 17 countries. In the pitch-black abyss, KM3NeT will study the trails of bluish light that neutrinos leave in the water. Capable of detecting dozens of these particles a day, it will help elucidate their quantum properties, which still defy our understanding.

The other LSPM instruments will permit the scientific community to study the life and chemistry of these depths. They will offer researchers insights into ocean acidification, deep-sea deoxygenation, marine radioactivity, and seismicity, and allow them to track cetacean populations as well as observe bioluminescent animals. This oceanographic instrumentation is integrated into the subsea observatory network of the EMSO European research infrastructure.

Adding a new layer to the already complex world of metaphysics.

An international team of scientists claim to have found a way to speed up, slow down, and even reverse the clock of a given system by taking advantage of the unusual properties of the quantum world, Spanish newspaper El País reports.

In a series of six papers, the team from the Austrian Academy of Sciences and the University of Vienna detailed their findings. The familiar laws of physics don’t map intuitively onto the subatomic world, which is made up of quantum particles called qubits that can technically exist in more than one state simultaneously, a phenomenon known as quantum entanglement.

Now, the researchers say they’ve figured out how to turn these quantum particles’ clocks forward and backward.

A slow-motion movie on sports television channels shows processes in hundredths of a second. By contrast, processes on the nanoscale take place in the so-called femtosecond range: For example, an electron needs only billionths of a second to orbit a hydrogen atom. Physicists around the world are using special instruments to capture such ultrafast nano-processes in films.

Researchers at Kiel University (CAU) have developed a new method for such films that is based on a different physical concept and thus allows further and more precise options for investigation. To do this, they combined an electron microscope with nanostructured metallic thin films that generate very short light pulses.

Continue reading “New analysis method developed for quantum and nanomaterials” »

Though quantum mechanics is an incredibly successful theory, nobody knows what it means. Scientists now must confront philosophy.

An Austrian and Spanish team demonstrated that a process can be ‘rewound’ to restore the components of an atom to their previous state.