(Phys.org)—Both high-valued diamond and low-prized graphite consist of exactly the same carbon atoms. The subtle but nevertheless important difference between the two materials is the geometrical configuration of their building blocks, with large consequences for their properties. There is no way, any kind of matter could be diamond and graphite at the same time.
However, this limitation does not hold for quantum matter, as a team of the Quantum Many-Body Physics Division of Prof. Immanuel Bloch (Max-Planck-Institute of Quantum Optics and Ludwig-Maximilians-Universität München) was now able to demonstrate in experiments with ultracold quantum gases. Under the influence of laser beams single atoms would arrange to clear geometrical structures (Nature, November 1st, 2012). But in contrast to classical crystals all possible configurations would exist at the same time, similar to the situation of Schrödinger’s cat which is in a superposition state of both “dead” and “alive”. The observation was made after transferring the particles to a highly excited so-called Rydberg-state. “Our experiment demonstrates the potential of Rydberg gases to realise exotic states of matter, thereby laying the basis for quantum simulations of, for example, quantum magnets,” Professor Immanuel Bloch points out.
An electrically driven on-chip light source of entangled photon pairs is developed by combining an InP gain section and Si3N4 microrings. A pair generation rate of 8,200 counts s−1 and a coincidence-to-accidental ratio of more than 80 are achieved around the wavelength of 1,550 nm.
We introduce quantum circuit learning (QCL) as an emerging regression algorithm for chemo-and materials-informatics. The supervised model, functioning on the rule of quantum mechanics, can process linear and smooth non-linear functions from small datasets (100 records). Compared with conventional algorithms, such as random forest, support vector machine, and linear regressions, the QCL can offer better predictions with some one-dimensional functions and experimental chemical databases. QCL will potentially help the virtual exploration of new molecules and materials more efficiently through its superior prediction performances.
The “spooky action at a distance” that once unnerved Einstein may be on its way to being as pedestrian as the gyroscopes that currently measure acceleration in smartphones.
Quantum entanglement significantly improves the precision of sensors that can be used to navigate without GPS, according to a new study in Nature Photonics.
“By exploiting entanglement, we improve both measurement sensitivity and how quickly we can make the measurement,” said Zheshen Zhang, associate professor of electrical and computer engineering at the University of Michigan and co-corresponding author of the study. The experiments were done at the University of Arizona, where Zhang was working at the time.
There are high expectations that quantum computers may deliver revolutionary new possibilities for simulating chemical processes. This could have a major impact on everything from the development of new pharmaceuticals to new materials. Researchers at Chalmers University have now, for the first time in Sweden, used a quantum computer to undertake calculations within a real-life case in chemistry.
“Quantum computers could in theory be used to handle cases where electrons and atomic nuclei move in more complicated ways. If we can learn to utilize their full potential, we should be able to advance the boundaries of what is possible to calculate and understand,” says Martin Rahm, Associate Professor in Theoretical Chemistry at the Department of Chemistry and Chemical Engineering, who has led the study.
Within the field of quantum chemistry, the laws of quantum mechanics are used to understand which chemical reactions are possible, which structures and materials can be developed, and what characteristics they have. Such studies are normally undertaken with the help of super computers, built with conventional logical circuits. There is however a limit for which calculations conventional computers can handle. Because the laws of quantum mechanics describe the behavior of nature on a subatomic level, many researchers believe that a quantum computer should be better equipped to perform molecular calculations than a conventional computer.
Hydrogen, the most abundant element in the universe, is found everywhere from the dust filling most of outer space to the cores of stars to many substances here on Earth. This would be reason enough to study hydrogen, but its individual atoms are also the simplest of any element with just one proton and one electron. For David Ceperley, a professor of physics at the University of Illinois Urbana-Champaign, this makes hydrogen the natural starting point for formulating and testing theories of matter.
Ceperley, also a member of the Illinois Quantum Information Science and Technology Center, uses computer simulations to study how hydrogen atoms interact and combine to form different phases of matter like solids, liquids, and gases. However, a true understanding of these phenomena requires quantum mechanics, and quantum mechanical simulations are costly. To simplify the task, Ceperley and his collaborators developed a machine learning technique that allows quantum mechanical simulations to be performed with an unprecedented number of atoms. They reported in Physical Review Letters that their method found a new kind of high-pressure solid hydrogen that past theory and experiments missed.
“Machine learning turned out to teach us a great deal,” Ceperley said. “We had been seeing signs of new behavior in our previous simulations, but we didn’t trust them because we could only accommodate small numbers of atoms. With our machine learning model, we could take full advantage of the most accurate methods and see what’s really going on.”
Providing increased resistance to outside interference, topological qubits create a more stable foundation than conventional qubits. This increased stability allows the quantum computer to perform computations that can uncover solutions to some of the world’s toughest problems.
While qubits can be developed in a variety of ways, the topological qubit will be the first of its kind, requiring innovative approaches from design through development. Materials containing the properties needed for this new technology cannot be found in nature—they must be created. Microsoft brought together experts from condensed matter physics, mathematics, and materials science to develop a unique approach producing specialized crystals with the properties needed to make the topological qubit a reality.
Donald Hoffman interview on spacetime, consciousness, and how biological fitness conceals reality. We discuss Nima Arkani-Hamed’s Amplituhedron, decorated permutations, evolution, and the unlimited intelligence.
The Amplituhedron is a static, monolithic, geometric object with many dimensions. Its volume codes for amplitudes of particle interactions & its structure codes for locality and unitarity. Decorated permutations are the deepest core from which the Amplituhedron gets its structure. There are no dynamics, they are monoliths as in 2001: A Space Odyssey.
Background. 0:00 Highlights. 6:55 The specific limits of evolution by natural selection. 10:50 Don’s born in a San Antonio Army hospital in 1955 (and his parents’ background) 14:44 As a teenager big question he wanted answered, “Are we just machines?“ 17:23 Don’s early work as a vision researcher; visual systems construct. 20:43 Carlos’s 3-part series on Fitness-Beats-Truth Theorem.
Fitness-Beats-Truth Theorem. 22:29 Clarifications on FBT: Game theory simulations & math proofs. 24:20 What does he mean I can’t see reality? Fitness payoff functions don’t know about the truth… 28:23 Evolution shapes sensory systems to guide adaptive behavior… consider the virtual reality headset 32:45 FBT doesn’t include costs for extra bits of information processing 34:40 Joscha Bach’s “There are no colors in the universe”… though even light itself isn’t fundamental! 36:36 Map-territory relationship 40:27 Infinite regress, Godel’s Incompleteness Theorem 42:27 Erik Hoel’s causal emergence theory 45:40 Don’s take on causality: there are no causal powers within spacetime What’s Beyond Spacetime? 50:50 Nima Arkani-Hamed’s Amplituhedron 53:00 What percentage of physicists would agree spacetime is doomed? 56:00 Amplituhedron a static, monolithic, geometric object with many dimensions… 59:23 Ties to holographic principle, Ads-CFT correspondence 1:03:13 Quantum error correction 1:05:23 James Gates’ adinkra animations linking electromagnetism & electron-like objects The Unlimited Intelligence 1:08:30 Does Don still meditate 3 hours every day? 1:11:30 “We’re here for the ride…” 1:12:27 All my theories are trivial, there’s an unlimited intelligence that transcends 1:14:00 Carlos meanders on meditation 1:15:50 “You can’t know the truth, but you can be the truth” 1:17:43 Explore-Exploit Tradeoff (foraging strategy) 1:19:15 “You’re absolutely knocking on the right doors here”… our 4D spacetime for some reason essential for consciousness 1:21:10 Why this world, with these symbols, this interface? 1:22:20 “My guess, one of the cheaper headsets” Conscious Realism 1:24:40 Precise, mathematical model of consciousness… the end of Cantor’s infinities 1:28:30 Fusions of Consciousness paper… bridges between interactions of conscious agents/Markovian dynamics → decorated permutations → the Amplituhedron → spacetime 1:35:20 In a meta way, did Don choose the highest fitness path for his career? 1:39:10 “Don’t believe my theory, not the final word” 1:41:00 Where to find more of Don’s work 🚩Links to Donald Hoffman & More 🚩 “Do we see reality as it is?” (Ted Talk 2015) • Do we see reality…
“Symmetry Does Not Entail Veridicality” lecture (Hoffman 2017) • Don Hoffman — “Sy…
