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Archive for the ‘quantum physics’ category: Page 128

Oct 20, 2023

Thirty Years Later, a Speed Boost for Quantum Factoring

Posted by in categories: computing, information science, mathematics, quantum physics, security

As Shor looked for applications for his quantum period-finding algorithm, he rediscovered a previously known but obscure mathematical theorem: For every number, there exists a periodic function whose periods are related to the number’s prime factors. So if there’s a number you want to factor, you can compute the corresponding function and then solve the problem using period finding — “exactly what quantum computers are so good at,” Regev said.

On a classical computer, this would be an agonizingly slow way to factor a large number — slower even than trying every possible factor. But Shor’s method speeds up the process exponentially, making period finding an ideal way to construct a fast quantum factoring algorithm.

Shor’s algorithm was one of a few key early results that transformed quantum computing from an obscure subfield of theoretical computer science to the juggernaut it is today. But putting the algorithm into practice is a daunting task, because quantum computers are notoriously susceptible to errors: In addition to the qubits required to perform their computations, they need many others doing extra work to keep them from failing. A recent paper by Ekerå and the Google researcher Craig Gidney estimates that using Shor’s algorithm to factor a security-standard 2,048-bit number (about 600 digits long) would require a quantum computer with 20 million qubits. Today’s state-of-the-art machines have at most a few hundred.

Oct 19, 2023

Controlling quantum biological electron tunnelling could help brain cancer patients

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

A technique based on modulating quantum processes inside human cells could improve treatment for glioblastoma.

Oct 19, 2023

Physicists Use Quantum Mechanics to Pull Energy out of Nothing

Posted by in categories: energy, quantum physics

“This is real physics, not science fiction”. Two physics experiments showed that it is possible to produce energy inside an energy vacuum.


The quantum energy teleportation protocol was proposed in 2008 and largely ignored. Now two independent experiments have shown that it works.

Oct 19, 2023

Nonclassical Advantage in Metrology Established via Quantum Simulations of Hypothetical Closed Timelike Curves

Posted by in category: quantum physics

We construct a metrology experiment in which the metrologist can sometimes amend the input state by simulating a closed timelike curve, a worldline that travels backward in time. The existence of closed timelike curves is hypothetical. Nevertheless, they can be simulated probabilistically by quantum-teleportation circuits. We leverage such simulations to pinpoint a counterintuitive nonclassical advantage achievable with entanglement. Our experiment echoes a common information-processing task: A metrologist must prepare probes to input into an unknown quantum interaction. The goal is to infer as much information per probe as possible. If the input is optimal, the information gained per probe can exceed any value achievable classically. The problem is that, only after the interaction does the metrologist learn which input would have been optimal.

Oct 19, 2023

Physicists create new form of antenna for radio waves

Posted by in categories: particle physics, quantum physics

University of Otago physicists have used a small glass bulb containing an atomic vapor to demonstrate a new form of antenna for radio waves. The bulb was “wired up” with laser beams and could therefore be placed far from any receiver electronics.

Dr. Susi Otto, from the Dodd-Walls Center for Photonic and Quantum Technologies, led the field testing of the portable atomic radio sensor. A paper on the creation was published in Applied Physics Letters.

Such sensors, that are enabled by atoms in a so-called Rydberg state, can provide superior performance over current antenna technologies as they are highly sensitive, have broad tunability, and small physical size, making them attractive for use in defense and communications.

Oct 19, 2023

The A.I. Dilemma

Posted by in categories: biotech/medical, quantum physics, robotics/AI, singularity

We need to ķeep up with china in human enhancement and biotechnology.


Tristan Harris and Aza Raskin discuss how existing A.I. capabilities already pose catastrophic risks to a functional society, how A.I. companies are caught in a race to deploy as quickly as possible without adequate safety measures, and what it would mean to upgrade our institutions to a post-A.I. world.

Continue reading “The A.I. Dilemma” »

Oct 17, 2023

The four types of planetary civilizations, explained by Michio Kaku

Posted by in categories: computing, quantum physics, space

Humanity is a type 0 civilization. Here’s what types 1, 2, and 3 look like, according to physicist Michio Kaku.

Is anybody out there? Renowned physicist Michio Kaku discusses we could identify and categorize advanced extraterrestrial civilizations.

Continue reading “The four types of planetary civilizations, explained by Michio Kaku” »

Oct 17, 2023

Solving quantum mysteries: New insights into 2D semiconductor physics

Posted by in categories: materials, quantum physics

Researchers from Monash University have unlocked fresh insights into the behavior of quantum impurities within materials.

The new, international theoretical study introduces a novel approach known as the “quantum virial expansion,” offering a powerful tool to uncover the complex quantum interactions in two-dimensional semiconductors.

This breakthrough holds potential to reshape our understanding of complex quantum systems and unlock exciting future applications utilizing novel 2D materials.

Oct 17, 2023

Thought experiments and conservation laws: Reevaluating quantum conservation principles

Posted by in categories: energy, law, quantum physics

Conservation laws are central to our understanding of the universe, and now scientists have expanded our understanding of these laws in quantum mechanics.

A conservation law in physics describes the preservation of certain quantities or properties in isolated physical systems over time, such as mass-energy, momentum, and electric charge.

Conservation laws are fundamental to our understanding of the universe because they define the processes that can or cannot occur in nature. For example, the conservation of momentum reveals that within a closed system, the sum of all momenta remains unchanged before and after an event, such as a collision.

Oct 16, 2023

There might be just one multiverse

Posted by in categories: alien life, quantum physics

The idea of the multiverse has at least two conceptually distinct sources in theoretical physics: quantum mechanics and cosmology. The many worlds of quantum mechanics are very different in terms of their nature and origin from cosmology’s multiverse. However, physicists have reason to believe that ultimately, these two distinct multiverses are in fact one and the same, writes David Wallace.

In big budget science-fiction and fantasy franchises, the “multiverse” is a collection of universes – some quite like our own, some differing from ours only in the way some historical event played out or some person’s life unfolded, some vastly different and filled with strange wonders. But in the drier and more disciplined world of modern physics, “multiverse” means… well, pretty much the same, only without the prospect of easily moving from one universe to the next. The multiverse of physics is revealed more subtly, by hints hidden in our observations and our theories.

Or rather: the multiverses of physics are revealed more subtly. For remarkably, physics gives us not one but three different multiverses, and reasons to accept all three.