Archive for the ‘quantum physics’ category: Page 13

Dec 7, 2023

Wormholes help resolve black hole information paradox

Posted by in categories: cosmology, mathematics, quantum physics

A RIKEN physicist and two colleagues have found that a wormhole—a bridge connecting distant regions of the Universe—helps to shed light on the mystery of what happens to information about matter consumed by black holes.

Einstein’s theory of predicts that nothing that falls into a black hole can escape its clutches. But in the 1970s, Stephen Hawking calculated that black holes should emit radiation when , the theory governing the microscopic realm, is considered. “This is called black hole evaporation because the black hole shrinks, just like an evaporating water droplet,” explains Kanato Goto of the RIKEN Interdisciplinary Theoretical and Mathematical Sciences.

This, however, led to a paradox. Eventually, the black hole will evaporate entirely—and so too will any information about its swallowed contents. But this contradicts a fundamental dictum of quantum physics: that information cannot vanish from the Universe. “This suggests that general relativity and quantum mechanics as they currently stand are inconsistent with each other,” says Goto. “We have to find a unified framework for quantum gravity.”

Dec 7, 2023

Resolving the black hole ‘fuzzball or wormhole’ debate

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

Black holes really are giant fuzzballs, a new study says.

The study attempts to put to rest the debate over Stephen Hawking’s famous information paradox, the problem created by Hawking’s conclusion that any data that enters a black hole can never leave. This conclusion accorded with the laws of thermodynamics, but opposed the fundamental laws of quantum mechanics.

“What we found from is that all the mass of a black hole is not getting sucked in to the center,” said Samir Mathur, lead author of the study and professor of physics at The Ohio State University. “The black hole tries to squeeze things to a point, but then the particles get stretched into these strings, and the strings start to stretch and expand and it becomes this fuzzball that expands to fill up the entirety of the black hole.”

Dec 7, 2023

Physicists ‘entangle’ individual molecules for the first time, hastening possibilities for quantum computing

Posted by in categories: computing, quantum physics

For the first time, a team of Princeton physicists have been able to link together individual molecules into special states that are quantum mechanically “entangled.” In these bizarre states, the molecules remain correlated with each other—and can interact simultaneously—even if they are miles apart, or indeed, even if they occupy opposite ends of the universe. This research was recently published in the journal Science.

“This is a breakthrough in the world of because of the fundamental importance of quantum entanglement,” said Lawrence Cheuk, assistant professor of physics at Princeton University and the senior author of the paper. “But it is also a breakthrough for practical applications because entangled molecules can be the for many future applications.”

These include, for example, quantum computers that can solve certain problems much faster than conventional computers, that can model complex materials whose behaviors are difficult to model, and that can measure faster than their traditional counterparts.

Dec 7, 2023

‘Off to the races’: DARPA, Harvard breakthrough brings quantum computing years closer

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

Quantum bits are potentially powerful but notoriously error-prone. Now a Harvard team says it has found a way to prevent mistakes — by manipulating individual atoms with laser beams — making quantum processing much more efficient.

Dec 7, 2023

Might There Be No Quantum Gravity After All?

Posted by in categories: information science, particle physics, quantum physics

A proposed model unites quantum theory with classical gravity by assuming that states evolve in a probabilistic way, like a game of chance.

Physicists’ best theory of matter is quantum mechanics, which describes the discrete (quantized) behavior of microscopic particles via wave equations. Their best theory of gravity is general relativity, which describes the continuous (classical) motion of massive bodies via space-time curvature. These two highly successful theories appear fundamentally at odds over the nature of space-time: quantum wave equations are defined on a fixed space-time, but general relativity says that space-time is dynamic—curving in response to the distribution of matter. Most attempts to solve this tension have focused on quantizing gravity, with the two leading proposals being string theory and loop quantum gravity. But new theoretical work by Jonathan Oppenheim at University College London proposes an alternative: leave gravity as a classical theory and couple it to quantum theory through a probabilistic mechanism [1].

Dec 7, 2023

IBM launches Quantum System Two and first 1,000+ qubit chip

Posted by in categories: computing, quantum physics

Computing giant IBM has launched three new innovations in quantum tech – the first utility-scale quantum computer, the first 1,000+ qubit chip and the most efficient quantum processor in terms of error correction.

IBM gave a sneak preview of its Quantum System Two during a conference last year. Following 12 months of additional research and development, it has now officially launched the system, which is described as “the first modular, utility-scale quantum computer.”

Dec 7, 2023

Superconductors’ Secret: Old Physics Law Stands the Test of Time in Quantum Material Conundrum

Posted by in categories: materials, quantum physics

This surprising result is important for understanding unconventional superconductors and other materials where electrons band together to act collectively.

Long before researchers discovered the electron and its role in generating electrical current, they knew about electricity and were exploring its potential. One thing they learned early on was that metals were great conductors of both electricity and heat.

Discovery of the Wiedemann-Franz Law.

Dec 7, 2023

Quantum theory the church Turing principle and the universal quantum computer by David Deutsch

Posted by in categories: computing, quantum physics

Shared with Dropbox.

Dec 7, 2023

DARPA-Funded Research Leads to Quantum Computing Breakthrough

Posted by in categories: quantum physics, supercomputing

Some new concepts for me but interesting and a good step forward.

A team of researchers working on DARPA’s Optimization with Noisy Intermediate-Scale Quantum devices (ONISQ) program has created the first-ever quantum circuit with logical quantum bits (qubits), a key discovery that could accelerate fault-tolerant quantum computing and revolutionize concepts for designing quantum computer processors.

The ONISQ program began in 2020 seeking to demonstrate a quantitative advantage of quantum information processing by leapfrogging the performance of classical-only supercomputers to solve a particularly challenging class of problem known as combinatorial optimization. The program pursued a hybrid concept to combine intermediate-sized “noisy”— or error-prone — quantum processors with classical systems focused specifically on solving optimization problems of interest to defense and commercial industry. Teams were selected to explore various types of physical, non-logical qubits including superconducting qubits, ion qubits, and Rydberg atomic qubits.

Continue reading “DARPA-Funded Research Leads to Quantum Computing Breakthrough” »

Dec 6, 2023

A novel microscope operates on the quantum state of single electrons

Posted by in categories: particle physics, quantum physics

Physicists at the University of Regensburg have found a way to manipulate the quantum state of individual electrons using a microscope with atomic resolution. The results of the study have now been published in the journal Nature.

We, and everything around us, consist of . The molecules are so tiny that even a speck of dust contains countless numbers of them. It is now routinely possible to precisely image such molecules with an , which works quite differently from an optical microscope: it is based on sensing tiny forces between a tip and the molecule under study.

Using this type of microscope, one can even image the internal structure of a molecule. Although one can watch the molecule this way, this does not imply knowing all its different properties. For instance, it is already very hard to determine which kind of atoms the molecule consists of.

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