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Archive for the ‘quantum physics’ category: Page 246

Jul 26, 2023

Characterizing atomic defects in 2D materials to determine suitability as quantum emitters

Posted by in categories: chemistry, quantum physics

The term molybdenum disulfide may sound familiar to some car drivers and mechanics. No wonder: the substance, discovered by U.S. chemist Alfred Sonntag in the 1940s, is still used today as a high-performance lubricant in engines and turbines, but also for bolts and screws.

This is due to the special chemical structure of this solid, whose individual material layers are easily displaceable relative to one another. However, molybdenum disulfide (chemically MoS2) not only lubricates well, but it is also possible to exfoliate a single atomic layer of this material or to grow it synthetically on a wafer scale.

The controlled isolation of a MoS2 monolayer was achieved only a few years ago, but is already considered a materials science breakthrough with enormous technological potential. The Empa team now wants to work with precisely this class of materials.

Jul 26, 2023

The Metaphysics of Panpsychism

Posted by in categories: media & arts, neuroscience, quantum physics

Alfred North Whitehead’s Process Philosophy, the Mystery of Consciousness and the Mind-Body Problem (2016)
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Compilation by Michael Schramm.
Background Music by Michael Schramm.
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Speakers & Quotations:
Charles Birch, Susan Blackmore, David J. Chalmers, Daniel C. Dennett, Freeman Dyson, David Ray Griffin, Charles Hartshorne, Nicholas Humphrey, Christof Koch, Colin McGinn, Thomas Nagel, Karl R. Popper, John R. Searle, Rupert Sheldrake, Galen Strawson, Alfred North Whitehead.

Tags:
panpsychism, consciousness, mind-body problem, process philosophy, process metaphysics, materialism, (property) dualism, quantum physics, indeterminism, free will.
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I have uploaded the resource document again and added a new link. Thanks for the interest!
Resources (new link):
https://theology-ethics.uni-hohenheim.de/fileadmin/einrichtu…ources.pdf.
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Jul 26, 2023

Researchers control the anomalous Hall effect and Berry curvature to create flexible quantum magnets

Posted by in categories: biotech/medical, computing, quantum physics

Some of our most important everyday items, such as computers, medical equipment, stereos, generators, and more, work because of magnets. We know what happens when computers become more powerful, but what might be possible if magnets became more versatile? What if one could change a physical property that defined their usability? What innovation might that catalyze?

It’s a question that MIT Plasma Science and Fusion Center (PSFC) research scientists Hang Chi, Yunbo Ou, Jagadeesh Moodera, and their co-authors explore in a new, open-access Nature Communications paper, “Strain-tunable Berry curvature in quasi-two-dimensional chromium telluride.”

Understanding the magnitude of the authors’ discovery requires a brief trip back in time: In 1,879, a 23-year-old graduate student named Edwin Hall discovered that when he put a magnet at right angles to a strip of metal that had a current running through it, one side of the strip would have a greater charge than the other. The was deflecting the current’s electrons toward the edge of the metal, a phenomenon that would be named the Hall effect in his honor.

Jul 26, 2023

Building a quantum computer in reverse

Posted by in categories: computing, quantum physics

Scaling has long been recognized as a major hurdle for quantum processors, along with a need for advances in quantum error correction and the control of quantum gates.

However, while rapid progress has been made in the latter two, far less progress has been made in the development of a CMOS-based scalable system, where the devices and qubits are sufficiently identical that the number of external control signals increases slowly with the number of qubits.

Therefore the development, and taping-out, of a CMOS-based scaling architecture has taken on new significance, as scaling has become the most critical remaining task for building a commercially viable quantum computer.

Jul 26, 2023

Sampling frequency thresholds for the quantum advantage of the quantum approximate optimization algorithm

Posted by in categories: information science, quantum physics

We compare the performance of the Quantum Approximate Optimization Algorithm (QAOA) with state-of-the-art classical solvers Gurobi and MQLib to solve the MaxCut problem on 3-regular graphs. We identify the minimum noiseless sampling frequency and depth p required for a quantum device to outperform classical algorithms. There is potential for quantum advantage on hundreds of qubits and moderate depth with a sampling frequency of 10 kHz. We observe, however, that classical heuristic solvers are capable of producing high-quality approximate solutions in linear time complexity. In order to match this quality for large graph sizes N, a quantum device must support depth p > 11. Additionally, multi-shot QAOA is not efficient on large graphs, indicating that QAOA p ≤ 11 does not scale with N. These results limit achieving quantum advantage for QAOA MaxCut on 3-regular graphs.

Jul 26, 2023

Simulating Spacetime with Quantum Mechanical Materials

Posted by in categories: materials, quantum physics

At the annual APS Division of Atomic, Molecular and Optical Physics meeting, physicists made the case for a new way of modeling a universe.

Jul 26, 2023

Three simple steps to make the longest graphene nanoribbon ever

Posted by in categories: particle physics, quantum physics

With 147 fused benzene rings and 920 conjugated atoms, the nanoribbon shows optoelectronic properties that could compete with quantum dots.

Jul 26, 2023

How splitting sound might lead to a new kind of quantum computer

Posted by in categories: computing, particle physics, quantum physics

When you turn on a lamp to brighten a room, you are experiencing light energy transmitted as photons, which are small, discrete quantum packets of energy. These photons must obey the sometimes strange laws of quantum mechanics, which, for instance, dictate that photons are indivisible, but at the same time, allow a photon to be in two places at once.

Similar to the photons that make up beams of light, indivisible quantum particles called phonons make up a beam of sound. These particles emerge from the collective motion of quadrillions of atoms, much as a “stadium wave” in a sports arena is due to the motion of thousands of individual fans. When you listen to a song, you’re hearing a stream of these very small quantum particles.

Jul 25, 2023

Quantum Leap: Scientists Develop Promising Building Blocks for Photonic Quantum Simulators

Posted by in categories: particle physics, quantum physics

Scientists at the Niels Bohr Institute, in cooperation with the University of Münster and Ruhr-Universität Bochum, developed new technology capable of processing the enormous amounts of information quantum systems generate. They’ve successfully linked deterministic single-photon.

A photon is a particle of light. It is the basic unit of light and other electromagnetic radiation, and is responsible for the electromagnetic force, one of the four fundamental forces of nature. Photons have no mass, but they do have energy and momentum. They travel at the speed of light in a vacuum, and can have different wavelengths, which correspond to different colors of light. Photons can also have different energies, which correspond to different frequencies of light.

Jul 25, 2023

‘Strange metal’ sends quantum researchers in circles

Posted by in categories: materials, quantum physics

A Yale-led team of physicists has discovered a circular pattern in the movement of electrons in a group of quantum materials known as “strange metals.”