Researchers have uncovered new phenomena in the study of fractional quantum Hall effects.
Their experiments, conducted under extreme conditions, have revealed unexpected states of matter, challenging existing theories and setting the stage for advancements in quantum computing and materials science.
Exploring the enigmatic world of quantum physics.
A new device converts a stream of microwave photons into an electric current with high efficiency, which will benefit quantum information technologies.
Technologies for quantum computing, sensing, and communication process information stored in quantum bits (qubits) by using microwave photons. But detecting such photons accurately and at high rates—to read out the changing states of a quantum computer, for example—is a challenge, since they have much less energy than visible or infrared photons. Now researchers have demonstrated a detection method based on the fact that a photon can assist in the quantum tunneling of an electron through a superconducting junction [1]. The technique converts a stream of microwave photons into a flow of electrons far more effectively than other methods, showing an efficiency of 83%, and it will be of immediate use in quantum technologies.
Building good detectors of microwave photons is inherently difficult, says Julien Basset of the University of Paris-Saclay, because such photons lack the energy needed to excite electrons in semiconductors into the conduction band, thereby generating a current that can be measured. Researchers have been pursuing several techniques, but none works well for a continuous stream of photons, in which multiple photons may arrive simultaneously. For such continuous operation, as would likely be required in many practical quantum information devices, the best efficiency demonstrated so far has been only a few percent, Basset says.
An analysis of the brightest gamma-ray burst ever observed reveals no difference in the propagation speed of different frequencies of light—placing some of the tightest constraints on certain violations of general relativity.
Understanding the nature of consciousness is one of the hardest problems in science. Some scientists have suggested that quantum mechanics, and in particular quantum entanglement, is the key to unraveling the phenomenon.
Quantum technology relies on qubits, the fundamental units of quantum computers, whose operation is influenced by quantum coherence time. Scientists believe that moiré excitons — electron-hole pairs trapped in overlapping moiré interference fringes — could serve as qubits in future nano-semiconductors. However, previous limitations in focusing light have caused optical interference, making it difficult to measure these excitons accurately.
Kyoto University researchers have developed a new technique to reduce moiré excitons, allowing for accurate measurement of quantum coherence time. Their findings, published in Nature Communications, reveal that the quantum coherence of a single moiré exciton remains stable for over 12 picoseconds at −269°C, significantly longer than that of excitons in traditional two-dimensional semiconductors. The confined moiré excitons in interference fringes help maintain quantum coherence, advancing the potential of quantum technology.
“We combined electron beam microfabrication techniques with reactive ion etching. By utilizing Michelson interferometry on the emission signal from a single moiré exciton, we could directly measure its quantum coherence time,” said Kazunari Matsuda of KyotoU’s Institute Advanced Energy.
Future space missions could use quantum technology to track water on Earth, explore the composition of moons and other planets, or probe mysterious cosmic phenomena.
At the risk of sounding a bit woo-woo, as any speculation about the “hard problem” of the unknowns of consciousness does, can’t both be true? In other words, is it possible that Schrödinger’s “total mind” is a kind of quantum reserve downloaded and differentially phased into qualia through the materialist medium of natural selection, which Edelman calls “neural Darwinism”? Is it the embodied human sensory organs interacting with their environment in feedback loops that unveils the unformed wave of fundamental consciousness through the particle of particular experience?
The correct answer is: Who knows?
“Who Knows?” would be an apt title for the best inventory to date of the myriad views on consciousness, from the metaphysical to the materialist, compiled by Robert Lawrence Kuhn and titled “A landscape of consciousness: toward a taxonomy of explanations and implications,” recently published in the journal “Progress in Biophysics and Molecular Biology.”
Posted in cosmology, particle physics, quantum physics
Avshalom Elitzur, Claudia de Rham and Harry Cliff debate the relationship between mystery and scientific discovery.
Does science eradicate mystery or expand it?
Watch the full debate at https://iai.tv/video/mystery-in-the-m…
We have the impression that science unravels the mysteries of the universe. But with every mystery solved, a new mystery emerges. The Big Bang gave us an explanation for the expanding universe but left the mystery of how it came about. Quantum mechanics accounted for the strange behaviour of subatomic particles, but led to the puzzle of its conflict with relativity. Dark energy made sense of an accelerating universe but led to the mystery of why we have no evidence for it. Is there a danger that we are making a fundamental mistake in imagining science can eradicate mystery, and do we need to think of science differently as a consequence?
Quantum is huge. Because quantum computing allows us to step beyond the current limitations of digital systems, it paves the way for a new era of computing machines with previously unthinkable power. Without recounting another simplified explanation of how quantum gets its power at length, we can reference the double-slit experiment and perhaps the spinning coin explanation.
A coin sat on a desk is either heads or tails, rather like the 1s and 0s that express the on or off values in binary code. Quantum theorists would prefer we think of the coin above the desk, spinning in the air. In this state, the coin is both heads and tails at the same time. This is because, at the quantum level, both values exist until we make an observation of its state at any given point in time. We could further increase the number of positions possible (literally known as quantum superposition) by altering the angle of view we take on the coin, which is somewhat similar to how we work with qubits in quantum mechanics.
So then, Schrödinger’s cat is both alive and dead at the same time and the dummies guide to quantum entanglement is out there on the web if needed. What matters most now is how we will make practical use of quantum computing and where it will be applied for best advantage.
