Archive for the ‘quantum physics’ category: Page 2

Apr 19, 2024

Compact quantum light processing: New findings lead to advances in optical quantum computing

Posted by in categories: computing, quantum physics

An international collaboration of researchers, led by Philip Walther at University of Vienna, have achieved a significant breakthrough in quantum technology, with the successful demonstration of quantum interference among several single photons using a novel resource-efficient platform. The work published in Science Advances represents a notable advancement in optical quantum computing that paves the way for more scalable quantum technologies.

Apr 19, 2024

Research reveals a surprising topological reversal in quantum systems

Posted by in categories: mathematics, quantum physics

In principle, one shouldn’t compare apples to oranges. However, in topology, which is a branch of mathematics, one must do just that. Apples and oranges, it turns out, are said to be topologically the same since they both lack a hole—in contrast to doughnuts or coffee cups, for instance, which both have one (the handle in the case of the cup), and thus are topologically equal.

Apr 19, 2024

In a global first, scientists create, store, and retrieve quantum data

Posted by in categories: computing, finance, internet, quantum physics

A collaboration of scientists from various universities in the UK and Europe have stored and retrieved data from quantum computers, marking a “crucial connection for ‘quantum internet,’” in a global first.

This is an essential step in quantum networking as the world gears up for the next generation of computing.

With its ultrafast computational speeds, quantum computing is touted to solve the world’s problems in designing new drugs, understanding the properties of materials, and optimizing financial risk.

Apr 19, 2024

Quantum Barkhausen noise detected for the first time

Posted by in categories: materials, quantum physics

Quantum Barkhausen noise, which arises from the cooperative quantum tunnelling of a huge number of magnetic spins, has been observed for the first time and may be the largest macroscopic quantum phenomena ever seen.

Researchers in the US and Canada have detected an effect known as quantum Barkhausen noise for the first time. The effect, which comes about thanks to the cooperative quantum tunnelling of a huge number of magnetic spins, may be the largest macroscopic quantum phenomena yet observed in the laboratory.

In the presence of a magnetic field, electron spins (or magnetic moments) in a ferromagnetic material all line up in the same direction – but not all at once. Instead, alignment occurs piecemeal, with different regions, or domains, falling into line at different times. These domains influence each other in a way that can be likened to an avalanche. Just as one clump of snow pushes on neighbouring clumps until the entire mass comes tumbling down, so does alignment spread through the domains until all spins point in the same direction.

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Apr 19, 2024

The big idea of Grand Unified Theories of physics

Posted by in categories: particle physics, quantum physics

I found this on NewsBreak: The big idea of Grand Unified Theories of physics.

Apr 19, 2024

School on Quantum Chaos

Posted by in categories: education, evolution, particle physics, quantum physics, space

Quantum chaos focuses on the quantum manifestations of classical chaos. A characteristic of classical chaos is the exponential sensitivity of the dynamics with respect to infinitesimal changes in the initial conditions. Thus, to classify classical dynamics it is sufficient to follow phase space trajectories starting infinitesimally close to each other and to determine the evolution of their distances with respect to each other with time. Because of the uncertainty relation, this is no longer possible in the corresponding quantum system. One important aspect of quantum chaos is the understanding of features of the classical dynamics in terms of the fluctuation properties in the energy spectra of closed quantum systems or of the fluctuations exhibited by the scattering matrix elements describing open ones. The fluctuation properties are predicted to be universal, that is, to be the same for systems belonging to the same universality class and exhibiting the same chaotic behavior in the corresponding classical dynamics and to be describable by random matrix theory. Furthermore, random-matrix models that had been developed for the scattering matrix associated with compound-nuclear reactions have been shown to be applicable to quantum-chaotic scattering processes. A second important aspect within the field of quantum chaos concerns the semiclassical approach. In this context, one of the most important achievements was the periodic orbit theory pioneered by Gutzwiller, which led to understanding the impact of the classical dynamics on the properties of the quantum system in terms of purely classical quantities. The focus of research within the field of quantum chaos has been extended to relativistic quantum systems and to many-body quantum systems with focus on random matrix theory and the semiclassical approach. In distinction to single-particle systems, many-body systems like atomic nuclei do not have a classical analogue. In recent years different measures of chaos and models have been developed. Here, a prominent model is the Sachdev-Ye-Kitaev model which serves as a paradigm for the study of quantum chaos in strongly interacting many-body systems. The school is aimed at PhD students, post-docs and outstanding master students and the first part will provide a survey of single-and many-body quantum chaos and applications based on random-matrix theory and the semiclassical approach. The second part of the school will focus on current aspects of research in the context of many-body quantum chaos. There is no registration fee and limited funds are available for travel and local expenses. Organizers: Hilda Cerdeira (IFT-UNESP, Brazil) Barbara Dietz-Pilatus (Institute for Basic Science (IBS), Republic of Korea)

Apr 19, 2024

Chaos: The real problem with quantum mechanics

Posted by in categories: mathematics, quantum physics, space

Check out the math & physics courses that I mentioned (many of which are free!) and support this channel by going to https://brilliant.org/Sabine/ where you can create your Brilliant account. The first 200 will get 20% off the annual premium subscription. You have probably heard people saying that the problem with quantum mechanics is that it’s non-local or that it’s impossible to understand or that it defies common sense. But the problem is much simpler, it’s that quantum mechanics is a linear theory and therefore doesn’t correctly reproduce chaos. Physicists have known this for a long time but it’s rarely discussed. In this video I explain what the problem is, what physicists have done to try and solve it, and why that solution doesn’t work. Subscribe to my weekly science newsletter: https://sabinehossenfelder.com/ You find the estimate for Saturn’s moon Hyperion in Zurek’s review https://arxiv.org/abs/quant-ph/0105127 A much easier to digest and more readable review by Michael Berry is here: https://michaelberryphysics.files.wor… you can find a brief summary on Sean Carroll’s blog https://www.preposterousuniverse.com/… 0:00 Intro 0:27 The trouble with Hyperion 4:04 The alleged solution 6:02 The trouble with the solution 7:46 What a real solution requires 10:31 Sponsor message.

Apr 19, 2024

How Chaos Control Is Changing The World

Posted by in categories: mathematics, quantum physics, robotics/AI

Try out my quantum mechanics course (and many others on math and science) on Brilliant using the link https://brilliant.org/sabine. You can get started for free, and the first 200 will get 20% off the annual premium subscription.

Physicists have known that it’s possible to control chaotic systems without just making them even more chaotic since the 1990s. But in the past 10 years this field has really exploded thanks to machine learning.

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Apr 19, 2024

Lamb Lecture 2024 ‘Quantum information, chaos, and space-time’

Posted by in category: quantum physics


Quantum gravity aims to find a description of spacetime and gravity that obeys the rules of quantum mechanics.

Apr 19, 2024

Quantum Internet Unleashed With HiFi’s Laser Breakthrough

Posted by in categories: computing, internet, quantum physics

The expansion of fiber optics is progressing worldwide, which not only increases the bandwidth of conventional Internet connections, but also brings closer the realization of a global quantum Internet. The quantum internet can help to fully exploit the potential of certain technologies. These include much more powerful quantum computing through the linking of quantum processors and registers, more secure communication through quantum key distribution or more precise time measurements through the synchronization of atomic clocks.

However, the differences between the glass fiber standard of 1,550 nm and the system wavelengths of the various quantum bits (qubits) realized to date represent a hurdle, because those qubits are mostly in the visible or near-infrared spectral range. Researchers want to overcome this obstacle with the help of quantum frequency conversion, which can specifically change the frequencies of photons while retaining all other quantum properties. This enables conversion to the 1,550 nm telecom range for low-loss, long-range transmission of quantum states.

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