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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. Their study is published in Nature.

The phenomena of the quantum world, which often seem bizarre from the perspective of the common everyday world, have long since found their way into technology. For example, entanglement: a quantum-physical connection between particles that links them in a strange way over arbitrarily long distances. It can be used, for example, in a quantum computer—a computing machine that, unlike a conventional computer, can perform numerous mathematical operations simultaneously. However, in order to use a quantum computer profitably, a large number of entangled particles must work together. They are the basic elements for calculations, so-called qubits.

“Photons, the particles of light, are particularly well suited for this because they are robust by nature and easy to manipulate,” says Philip Thomas, a doctoral student at the Max Planck Institute of Quantum Optics (MPQ) in Garching near Munich. Together with colleagues from the Quantum Dynamics Division led by Prof. Gerhard Rempe, he has now succeeded in taking an important step towards making photons usable for technological applications such as quantum computing: For the first time, the team generated up to 14 entangled photons in a defined way and with high efficiency.

A new study by theoretical physicists has made progress toward identifying how particles and cells give rise to large-scale dynamics that we experience as the passage of time.

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

Fundamentally, the arrow of time emerges from the second law of thermodynamics. This is 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 propensity toward disorder is the fundamental reason why we experience time flowing in one direction.

One hypothesis for the nature of dark matter is that some of it could be self-interacting, meaning the individual particles interact slightly with one another.

Exactly like a quasicrystal, this arrangement is ordered without repetition. Similar to a quasicrystal, it’s a single-dimensional representation of a 2-dimensional pattern. As a consequence of the flattening of dimensions, the system is given two time symmetries instead of just one: the system is given another dimension of time that does not exist.

Nevertheless, quantum computers remain extremely complex experimental systems, so it is not yet known whether the benefits of the theory will hold true in actual qubits.

The experientialists tested the theory using Quantinuum’s quantum computer. Periodically and using Fibonacci sequences, laser light was pulsed at the computer’s qubits.

We might start to see atoms interacting with each other in ways “we have not yet seen.”

University of Birmingham researchers have demonstrated how unique vibrations, which are caused by interactions between the two stars’ tidal fields as they approach each other, affect gravitational-wave observations.

Taking these movements into account could significantly improve our understanding of the data collected by the Advanced LIGO and Virgo instruments, according to a press release published on the institute’s official website on Thursday.

Continue reading “Looking inside a neutron star — new model will improve insights gleaned from gravitational waves” »

A team of Chinese scientists report on a new method for entangling photons that they say could make quantum networks and quantum computing more practical, according to the South China Post.

In a study published in Nature Photonics, the team from the University of Science and Technology of China said that the new way to produce entangled photons is extremely efficient. The work was led by Jian-Wei Pan, one of the world’s leading quantum researcher from the Hefei National Research Center for Physical Sciences at the Microscale, the University of Science and Technology of China and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China.

Entangled photons are needed for certain forms of quantum communication and computing. These technologies require the ability to efficiently produce large numbers of particles — in this case, photons — that can remain entangled even when separated by vast distances to process and protect information. Specifically, the technology could be used in quantum relays that are used in long-distance, attack-proof quantum communication, the newspaper reports.

The textbook description of a proton says it contains three smaller particles — two up quarks and a down quark — but a new analysis has found strong evidence that it also holds a charm quark.

Reflections from Brookhaven Lab physicists on culmination of 2020–22 U.S. high-energy physics community planning process.

https://youtube.com/watch?v=QfBG3AbW6QA

A novel method for measuring nanoparticle size could have applications in industry and basic materials science research.

Nanoparticles are present in everything from paints to pharmaceutical products. While nanoparticles have many important characteristics, such as molecular composition and shape, it is their size that determines many chemical and physical properties. A new technique relying on an optical vortex—a laser beam whose wave fronts twist around a dark central region—allows researchers to characterize nanoparticle size rapidly and continuously [1]. This light-based size probe might one day find applications in numerous industrial settings and aid fundamental materials science research.

Continue reading “Optical Vortex Sizes Up Nanoparticles” »