Posted in cosmology, quantum physics, robotics/AI
I recently read an interesting book on reality, entitled The Fabric of Reality. In the book, David Deutsch constructs a unified theory of reality by combining four fundamental theories: 1. Quantum mechanics (multiverse interpretation). 2. Turing principle of computers and artificial intelligence. 3. Popperian epistemology. 4. Darwinian evolution. Deutsch says: In all cases the theory […].
HRL Laboratories, LLC, has published the first demonstration of universal control of encoded spin qubits. This newly emerging approach to quantum computation uses a novel silicon-based qubit device architecture, fabricated in HRL’s Malibu cleanroom, to trap single electrons in quantum dots. Spins of three such single electrons host energy-degenerate qubit states, which are controlled by nearest-neighbor contact interactions that partially swap spin states with those of their neighbors.
Posted online ahead of publication in the journal Nature, the HRL experiment demonstrated universal control of their encoded qubits, which means the qubits can be used successfully for any kind of quantum computational algorithm implementation. The encoded silicon/silicon germanium quantum dot qubits use three electron spins and a control scheme whereby voltages applied to metal gates partially swap the directions of those electron-spins without ever aligning them in any particular direction. The demonstration involved applying thousands of these precisely calibrated voltage pulses in strict relation to one another over the course of a few millionths of a second. The article is entitled “Universal logic with encoded spin qubits in silicon.”
The quantum coherence offered by the isotopically enriched silicon used, the all-electrical and low-crosstalk-control of partial swap operations, and the configurable insensitivity of the encoding to certain error sources combine to offer a strong pathway toward scalable fault tolerance and computational advantage, major steps toward a commercial quantum computer.
Photon-enabled quantum communication could send exponential amounts of data securely over interstellar distances, potentially to intelligent ET societies.
Quantum bits inspired by Schrödinger’s cat could allow quantum computers to make fewer mistakes and more efficiently crack algorithms used for encryption.
After 85 years of searching, researchers have confirmed the existence of a massless particle called the Weyl fermion for the first time ever. With the unique ability to behave as both matter and anti-matter inside a crystal, this strange particle can create electrons that have no mass.
The discovery is huge, not just because we finally have proof that these elusive particles exist, but because it paves the way for far more efficient electronics, and new types of quantum computing. “Weyl fermions could be used to solve the traffic jams that you get with electrons in electronics — they can move in a much more efficient, ordered way than electrons,” lead researcher and physicist M. Zahid Hasan from Princeton University in the US told Anthony Cuthbertson over at IBTimes. “They could lead to a new type of electronics we call ‘Weyltronics’.”
So what exactly is a Weyl fermion? Although we’re often taught in high school science that the Universe is made up of atoms, from a particle physics point of view, everything is actually made up of fermions and bosons. Put very simply, fermions are the building blocks that make up all matter, such as electrons, and bosons are the things that carry force, such as photons.
Experts consider glass nanoparticles kept inside extreme vacuum layers as potential platforms for examining the quantum world’s limits. However, a question in the field of quantum theory remains unanswered: at which size does an object start being described by quantum physics laws rather than classical physics laws?
Achieving Quantum-State Cooling in More Than One Direction Is Challenging
SciTechDaily reports that a research team attempted to precisely answer the question through the ERC-Synergy project Q-Xtreme. The team comprised Lukas Novotny from ETH Zurich, Markus Aspelmeyer from the University of Vienna, Oriol Romero-Isart from the University of Innsbruck, and Romain Quidant from Zurich.
Determining the passage of time in our world of ticking clocks and oscillating pendulums is a simple case of counting the seconds between ‘then’ and ‘now’.
Down at the quantum scale of buzzing electrons, however, ‘then’ can’t always be anticipated. Worse still, ‘now’ often blurs into a haze of vagueness. A stopwatch simply isn’t going to work for some scenarios.
A potential solution could be found in the very shape of the quantum fog itself, according to a 2022 study by researchers from Uppsala University in Sweden.
HRL Laboratories, LLC, has published the first demonstration of universal control of encoded spin qubits. This newly emerging approach to quantum computation uses a novel silicon-based qubit device architecture, fabricated in HRL’s Malibu cleanroom, to trap single electrons in quantum dots. Spins of three such single electrons host energy-degenerate qubit states, which are controlled by nearest-neighbor contact interactions that partially swap spin states with those of their neighbors.
Scientists are vigorously competing to transform the counterintuitive discoveries about the quantum realm from a century past into technologies of the future. The building block in these technologies is the quantum bit, or qubit. Several different kinds are under development, including ones that use defects within the symmetrical structures of diamond and silicon. They may one day transform computing, accelerate drug discovery, generate unhackable networks and more.
Working with researchers from several universities, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have discovered a method for introducing spinning electrons as qubits in a host nanomaterial. Their test results revealed record long coherence times—the key property for any practical qubit because it defines the number of quantum operations that can be performed in the lifetime of the qubit.
Electrons have a property analogous to the spin of a top, with a key difference. When tops spin in place, they can rotate to the right or left. Electrons can behave as though they were rotating in both directions at the same time. This is a quantum feature called superposition. Being in two states at the same time makes electrons good candidates for spin qubits.
Short and sweet. Everyone needs a daily dose of Sabine.
Is science close to explaining everything about our universe? Physicist Sabine Hossenfelder reacts.
Up next, Physics’ greatest mystery: Michio Kaku explains the God Equation ► https://youtu.be/B1GO1HPLp7Y
In his 1996 book “The End of Science”, John Horgan argued that scientists were close to answering nearly all of the big questions about our Universe. Was he right?
The theoretical physicist Sabine Hossenfelder doesn’t think so. As she points out, the Standard Model of physics, which describes the behavior of particles and their interactions, is still incomplete as it does not include gravity. What’s more, the measurement problem in quantum mechanics remains unsolved, and understanding this could lead to significant technological advancements.
