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Category: quantum physics – Page 606

How Did the First Atom Form? Where did it come from? | Big Bang Nucleosynthesis

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Background videos:
Fundamental forces: https://youtu.be/669QUJrF4u0
Electroweak theory: https://youtu.be/u05VK0pSc7I
Is Big Bang hidden in gravity waves: https://youtu.be/VXr1mzY2GnY
Cosmic Microwave background: https://youtu.be/XcXCrFIivyk.

Errata:
12:26 — Helium-3 has 2 protons and 1 Neutron.

Chapters:
0:00 — How many atoms are there?
1:01 — We don’t know what happened at or before t=0
3:34 — Cosmic inflation.
5:27 — What we do know.
8:29 — How protons and neutrons formed.
10:41 — How charged nucleons formed.
13:47 — How neutral atoms formed.
15:24 — How to learn more about atoms.

Summary:
Where did the first atom come from? The short answer is the big bang. In the early universe there was an immense amount of energy, The energy condensed, atoms formed. But there’s a lot more that happened, which will be explained here.

The big bang is often thought of as the theory explaining the beginning. but it’s not. We don’t know when the universe actually started, or whether it did. Our best theory of the early universe is the standard model of cosmology, We can only go back to one Planck time, about 10^−43 seconds. This is the smallest unit of time that can theoretically exist according to quantum mechanics. We don’t know what came before this.

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Magnetene — A Graphene-Like 2D Material — Leverages Quantum Effects To Achieve Ultra-Low Friction

Magnetene could have useful applications as a lubricant in implantable devices or other micro-electro-mechanical systems.

A team of researchers from University of Toronto Engineering and Rice University have reported the first measurements of the ultra-low-friction behaviour of a material known as magnetene. The results point the way toward strategies for designing similar low-friction materials for use in a variety of fields, including tiny, implantable devices.

Magnetene is a 2D material, meaning it is composed of a single layer of atoms. In this respect, it is similar to graphene 0, a material that has been studied intensively for its unusual properties — including ultra-low friction — since its discovery in 2004.

Magnetene: Graphene-like 2D material leverages quantum effects to achieve ultra-low friction

A team of researchers from University of Toronto Engineering and Rice University have reported the first measurements of the ultra-low-friction behavior of a material known as magnetene. The results point the way toward strategies for designing similar low-friction materials for use in a variety of fields, including tiny, implantable devices.

Modeling quantum spin liquids using machine learning

The properties of a complex and exotic state of a quantum material can be predicted using a machine learning method created by a RIKEN researcher and a collaborator. This advance could aid the development of future quantum computers.

We have all faced the agonizing challenge of choosing between two equally good (or bad) options. This frustration is also felt by when they feel two competing forces in a special type of quantum system.

In some magnets, particle spins—visualized as the axis about which a particle rotates—are all forced to align, whereas in others they must alternate in direction. But in a small number of materials, these tendencies to align or counter-align compete, leading to so-called frustrated magnetism. This frustration means that the spin fluctuates between directions, even at absolute zero temperature where one would expect stability. This creates an exotic state of matter known as a .

Energizer atoms: Physicists find new way to keep atoms excited

JILA researchers have tricked nature by tuning a dense quantum gas of atoms to make a congested “Fermi sea,” thus keeping atoms in a high-energy state, or excited, for about 10% longer than usual by delaying their normal return to the lowest-energy state. The technique might be used to improve quantum communication networks and atomic clocks.

Quantum systems such as atoms that are excited above their resting state naturally calm down, or decay, by releasing light in quantized portions called photons. This common process is evident in the glow of fireflies and emission from LEDs. The rate of decay can be engineered by modifying the environment or the internal properties of the atoms. Previous research has modified the electromagnetic environment; the new work focuses on the atoms.

The new JILA method relies on a rule of the quantum world known as the Pauli exclusion principle, which says identical fermions (a category of particles) can’t share the same quantum states at the same time. Therefore, if enough fermions are in a crowd—creating a Fermi sea—an excited fermion might not be able to fling out a photon as usual, because it would need to then recoil. That recoil could land it in the same quantum state of motion as one of its neighbors, which is forbidden due to a mechanism called Pauli blocking.

Are Black Holes Actually Fuzzballs?

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Black holes are a paradox. They are paradoxical because they simultaneously must exist but can’t, and so they break physics as we know it. Many physicists will tell you that the best way to fix broken physics is with string. String theory, in fact. And in the black holes of string theory — fuzzballs — are perhaps even weirder than the regular type.

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Strange quantum effect predicted 30 years ago has now been observed

If you get a dense quantum gas cloud cold enough, you can see right through it. This phenomenon, called Pauli blocking, happens because of the same effects that give atoms their structure, and now it has been observed for the first time.

“This has been a theoretical prediction for more than three decades,” says Amita Deb at the University of Otago in New Zealand, a member of one of three teams that have now independently seen this. “This is the first time this been proven experimentally.”

Pauli blocking occurs in gases made up of a type of particle called a fermion, a category that includes the protons, neutrons and electrons that make up all atoms. These particles obey a rule called the Pauli exclusion principle, which dictates that no two identical fermions can occupy the same quantum state in a given system.

Adding Sound to Quantum Simulations: Creating a Lattice of Light and Atoms That Can Vibrate

Aiming to emulate the quantum characteristics of materials more realistically, researchers have figured out a way to create a lattice of light and atoms that can vibrate – bringing sound to an otherwise silent experiment.

When sound was first incorporated into movies in the 1920s, it opened up new possibilities for filmmakers such as music and spoken dialogue. Physicists may be on the verge of a similar revolution, thanks to a new device developed at Stanford University that promises to bring an audio dimension to previously silent quantum science experiments.

In particular, it could bring sound to a common quantum science setup known as an optical lattice, which uses a crisscrossing mesh of laser beams to arrange atoms in an orderly manner resembling a crystal. This tool is commonly used to study the fundamental characteristics of solids and other phases of matter that have repeating geometries. A shortcoming of these lattices, however, is that they are silent.

Atom Computing: A Quantum Computing Startup That Believes It Can Ultimately Win The Qubit Race

While traditional computers use magnetic bits to represent a one or a zero for computation, quantum computers use quantum bits or qubits to represent a one or a zero or simultaneously any number in between.

Today’s quantum computers use several different technologies for qubits. But regardless of the technology, a common requirement for all quantum computing qubits is that it must be scalable, high quality, and capable of fast quantum interaction with each other.

IBM uses superconducting qubits on its huge fleet of about twenty quantum computers. Although Amazon doesn’t yet have a quantum computer, it plans to build one using superconducting hardware. Honeywell and IonQ both use trapped-ion qubits made from a rare earth metal called ytterbium. In contrast, Psi Quantum and Xanadu use photons of light.

Atom computing chose to use different technology — nuclear-spin qubits made from neutral atoms. Phoenix, the name of Atom’s first-generation, gate-based quantum computer platform, uses 100 optically trapped qubits.

Full Story:

Atom Computing describes itself as “a company obsessed with building the world’s most scalable quantum computers out of optically trapped neutral atoms.” The company recently revealed it had spent the past two years secretly building a quantum computer using Strontium atoms as its units of computation.

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