Archive for the ‘quantum physics’ category: Page 400
Dec 13, 2020
Physicists fine tune chemical reaction rates for ultracold molecules
Posted by Genevieve Klien in categories: chemistry, particle physics, quantum physics
New technique could be useful for quantum information processing.
A new technique to cool reactive molecules to temperatures low enough to achieve quantum degeneracy – something not generally possible before – has been created by researchers in the US. In this temperature regime, the dominance of quantum effects over thermal fluctuations should allow researchers to study new quantum properties of molecules. As a first example, the researchers demonstrated how a slight change in applied electric field can alter the reaction rate between molecules by three orders of magnitude. The researchers hope their platform will enable further exploration of molecular quantum degeneracy, with potential applications ranging from quantum many body physics to quantum information processing.
When atoms are cooled close to absolute zero, the blur created by thermal effects that govern their behaviour in the classical world around us is removed, making their quantum nature clear. This has led to some fascinating discoveries. In ultracold quantum bosonic or fermion-pair quantum gases, for example, all the atoms in a trap can simultaneously occupy the quantum ground state, resulting in a wavefunction that is macroscopic.
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Dec 13, 2020
Danish researchers developed nanochip that could achieve ‘quantum supremacy’
Posted by Quinn Sena in categories: computing, quantum physics
Specialists from the University of Copenhagen created a chip that could be used to build a future quantum simulator.
Dec 12, 2020
Black Holes Gain new Powers When They Spin Fast Enough
Posted by Genevieve Klien in categories: cosmology, mathematics, quantum physics
Fast spinning black holes could have features different from those predicted by general relativity.
General relativity is a profoundly complex mathematical theory, but its description of black holes is amazingly simple. A stable black hole can be described by just three properties: its mass, its electric charge, and its rotation or spin. Since black holes aren’t likely to have much charge, it really takes just two properties. If you know a black hole’s mass and spin, you know all there is to know about the black hole.
This property is often summarized by the no-hair theorem. Specifically, the theorem asserts that once matter falls into a black hole, the only characteristic that remains is mass. You could make a black hole out of a Sun’s worth of hydrogen, chairs, or those old copies of National Geographic from Grandma’s attic, and there would be no difference. Mass is mass as far as general relativity is concerned. In every case the event horizon of a black hole is perfectly smooth, with no extra features. As Jacob Bekenstein said, black holes have no hair.
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Dec 11, 2020
Physicists use antiferromagnetic rust to carry information over long distances at room temperature
Posted by Saúl Morales Rodriguéz in categories: computing, mobile phones, particle physics, quantum physics
Be it with smartphones, laptops, or mainframes: The transmission, processing, and storage of information is currently based on a single class of material—as it was in the early days of computer science about 60 years ago. A new class of magnetic materials, however, could raise information technology to a new level. Antiferromagnetic insulators enable computing speeds that are a thousand times faster than conventional electronics, with significantly less heating. Components could be packed closer together and logic modules could thus become smaller, which has so far been limited due to the increased heating of current components.
Information transfer at room temperature
So far, the problem has been that the information transfer in antiferromagnetic insulators only worked at low temperatures. But who wants to put their smartphones in the freezer to be able to use it? Physicists at Johannes Gutenberg University Mainz (JGU) have now been able to eliminate this shortcoming, together with experimentalists from the CNRS/Thales lab, the CEA Grenoble, and the National High Field Laboratory in France as well as theorists from the Center for Quantum Spintronics (QuSpin) at the Norwegian University of Science and Technology. “We were able to transmit and process information in a standard antiferromagnetic insulator at room temperature—and to do so over long enough distances to enable information processing to occur”, said JGU scientist Andrew Ross. The researchers used iron oxide (α-Fe2O3), the main component of rust, as an antiferromagnetic insulator, because iron oxide is widespread and easy to manufacture.
Dec 10, 2020
Black Hole Atom as a Dark Matter Particle Candidate
Posted by Quinn Sena in categories: cosmology, particle physics, quantum physics
Circa 2014
We propose the new dark matter particle candidate—the “black hole atom,” which is an atom with the charged black hole as an atomic nucleus and electrons in the bound internal quantum states. As a simplified model we consider the central Reissner-Nordström black hole with the electric charge neutralized by the internal electrons in bound quantum states. For the external observers these objects would look like the electrically neutral Schwarzschild black holes. We suppose the prolific production of black hole atoms under specific conditions in the early universe.
Dec 10, 2020
‘Electronic amoeba’ finds approximate solution to traveling salesman problem in linear time
Posted by Quinn Sena in categories: quantum physics, robotics/AI, supercomputing
Researchers at Hokkaido University and Amoeba Energy in Japan have, inspired by the efficient foraging behavior of a single-celled amoeba, developed an analog computer for finding a reliable and swift solution to the traveling salesman problem—a representative combinatorial optimization problem.
Many real-world application tasks such as planning and scheduling in logistics and automation are mathematically formulated as combinatorial optimization problems. Conventional digital computers, including supercomputers, are inadequate to solve these complex problems in practically permissible time as the number of candidate solutions they need to evaluate increases exponentially with the problem size—also known as combinatorial explosion. Thus new computers called Ising machines, including quantum annealers, have been actively developed in recent years. These machines, however, require complicated pre-processing to convert each task to the form they can handle and have a risk of presenting illegal solutions that do not meet some constraints and requests, resulting in major obstacles to the practical applications.
These obstacles can be avoided using the newly developed ‘electronic amoeba,’ an analog computer inspired by a single-celled amoeboid organism. The amoeba is known to maximize nutrient acquisition efficiently by deforming its body. It has shown to find an approximate solution to the traveling salesman problem (TSP), i.e., given a map of a certain number of cities, the problem is to find the shortest route for visiting each city exactly once and returning to the starting city. This finding inspired Professor Seiya Kasai at Hokkaido University to mimic the dynamics of the amoeba electronically using an analog circuit, as described in the journal Scientific Reports. “The amoeba core searches for a solution under the electronic environment where resistance values at intersections of crossbars represent constraints and requests of the TSP,” says Kasai. Using the crossbars, the city layout can be easily altered by updating the resistance values without complicated pre-processing.
Dec 10, 2020
Black Holes Are ‘Portals to Other Universes,’ According to New Quantum Results
Posted by Quinn Sena in categories: cosmology, quantum physics, singularity
O,.o.
Black holes may not end in a crushing singularity as previously thought, but rather open up passageways into whole other universes.
Dec 10, 2020
Simulating subatomic physics on a quantum computer
Posted by Genevieve Klien in categories: computing, quantum physics
Scientists show how quantum computing could be a game-changer in our understanding of quantum processes.
Dec 9, 2020
New tools ‘turn on’ quantum gases of ultracold molecules
Posted by Saúl Morales Rodriguéz in categories: chemistry, computing, quantum physics
JILA researchers have developed tools to “turn on” quantum gases of ultracold molecules, gaining control of long-distance molecular interactions for potential applications such as encoding data for quantum computing and simulations.
The new scheme for nudging a molecular gas down to its lowest energy state, called quantum degeneracy, while suppressing chemical reactions that break up molecules finally makes it possible to explore exotic quantum states in which all the molecules interact with one another.
The research is described in the Dec. 10 issue of Nature. JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder.