Lifeboat Foundation

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 fundamental particles 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 quantum spin liquid.

The universe could house black holes smaller than atoms — and they may have left their fingerprints on the moon.

Soot is one of the world’s worst contributors to climate change. Its impact is similar to global methane emissions and is second only to carbon dioxide in its destructive potential. This is because soot particles absorb solar radiation, which heats the surrounding atmosphere, resulting in warmer global temperatures. Soot also causes several other environmental and health problems including making us more susceptible to respiratory viruses.

Soot only persists in the atmosphere for a few weeks, suggesting that if these emissions could be stopped then the air could rapidly clear. This has recently been demonstrated during recent lockdowns, with some major cities reporting clear skies after industrial emissions stopped.

But soot is also part of our future. Soot can be converted into the useful carbon black product through thermal treatment to remove any harmful components. Carbon blacks are critical ingredients in batteries, tires and paint. If these carbons are made small enough they can even be made to fluoresce and have been used for tagging biological molecules, in catalysts and even in solar cells.

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.

For the satellites spinning around Earth, using electricity to ionize and push particles of xenon gets them to go where they need to go. While xenon atoms ionize easily and are heavy enough to build thrust, the gas is rare and expensive, not to mention difficult to store.

Thanks to new research, we could soon have an alternative. Enter iodine.

Full in-orbit operation of a satellite powered by iodine gas has now been carried out by space tech company ThrustMe, and the technology promises to lead to satellite propulsion systems that are more efficient and affordable than ever before.

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.

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.

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.

Continue reading “Atom Computing: A Quantum Computing Startup That Believes It Can Ultimately Win The Qubit Race” »

OAKLAND, Calif. Nov 17 (Reuters) — A new quantum computer startup born from researchers at Harvard University and Massachusetts Institute of Technology (MIT) called QuEra Computing said on Wednesday it raised $17 million from investors, including Japanese e-commerce giant Rakuten Inc (4755.T).

It’s the latest quantum computer hardware maker to come out of the lab at a time when funding for the nascent technology is booming. read more

While there are various technologies for creating so-called quantum bits or qubits where the computations happen, QuEra’s qubits use neutral atoms in a vacuum chamber and use lasers to cool and control them.