Lifeboat Foundation

Researchers perform experiments that can add or subtract a single quantum of sound—with surprising results when applied to noisy sound fields.

Quantum mechanics tells us that physical objects can have both wave and particle properties. For instance, a single particle—or quantum—of light is known as a photon, and, in a similar fashion, a single quantum of sound is known as a phonon, which can be thought of as the smallest unit of sound energy.

A team of researchers spanning Imperial College London, University of Oxford, the Niels Bohr Institute, University of Bath, and the Australian National University have performed an experiment that can add or subtract a single phonon to a high-frequency sound field using interactions with laser light.

I like this idea. I don’t want AI to be a black box, I want to know what’s happening and how its doing it.

The field of artificial intelligence has created computers that can drive cars, synthesize chemical compounds, fold proteins, and detect high-energy particles at a superhuman level.

However, these AI algorithms cannot explain the thought processes behind their decisions. A computer that masters protein folding and also tells researchers more about the rules of biology is much more useful than a computer that folds proteins without explanation.

Continue reading “How Explainable Artificial Intelligence Can Help Humans Innovate” »

Researchers at the Paul Scherrer Institute PSI have put forward a detailed plan of how faster and better defined quantum bits — qubits — can be created. The central elements are magnetic atoms from the class of so-called rare-earth metals, which would be selectively implanted into the crystal lattice of a material. Each of these atoms represents one qubit. The researchers have demonstrated how these qubits can be activated, entangled, used as memory bits, and read out. They have now published their design concept and supporting calculations in the journal PRX Quantum.

On the way to quantum computers, an initial requirement is to create so-called quantum bits or “qubits”: memory bits that can, unlike classical bits, take on not only the binary values of zero and one, but also any arbitrary combination of these states. “With this, an entirely new kind of computation and data processing becomes possible, which for specific applications means an enormous acceleration of computing power,” explains PSI researcher Manuel Grimm, first author of a new paper on the topic of qubits.

Even if you weren’t a physics major, you’ve probably heard something about the Higgs boson.

Scientists at the U.S. Department of Energy’s Ames Laboratory and collaborators at Brookhaven National Laboratory and the University of Alabama at Birmingham have discovered a new light-induced switch that twists the crystal lattice of the material, switching on a giant electron current that appears to be nearly dissipationless. The discovery was made in a category of topological materials that holds great promise for spintronics, topological effect transistors, and quantum computing.

Weyl and Dirac semimetals can host exotic, nearly dissipationless, electron conduction properties that take advantage of the unique state in the crystal lattice and electronic structure of the material that protects the electrons from doing so. These anomalous electron transport channels, protected by symmetry and topology, don’t normally occur in conventional metals such as copper. After decades of being described only in the context of theoretical physics, there is growing interest in fabricating, exploring, refining, and controlling their topologically protected electronic properties for device applications. For example, wide-scale adoption of quantum computing requires building devices in which fragile quantum states are protected from impurities and noisy environments. One approach to achieve this is through the development of topological quantum computation, in which qubits are based on “symmetry-protected” dissipationless electric currents that are immune to noise.

“Light-induced lattice twisting, or a phononic switch, can control the crystal inversion symmetry and photogenerate giant electric current with very small resistance,” said Jigang Wang, senior scientist at Ames Laboratory and professor of physics at Iowa State University. “This new control principle does not require static electric or magnetic fields, and has much faster speeds and lower energy cost.”

Direct observation of an ion moving through a Bose-Einstein condensate identifies the effect of ion-atom collisions on charge transport in an ultracold gas.

When you expose mobile electrical charges in a medium to an electrical field, current flows. The charges are accelerated by the field, but collisions within the medium give rise to a kind of friction effect, which limits the velocity of the charges and thus the current. This universal concept, called diffusive transport, describes a large range of media, such as metallic conductors, electrolytic solutions, and gaseous plasmas. But in a quantum system, such as a superconductor or a superfluid, other collective effects can influence the transport through the medium. Now, a group led by Florian Meinert and Tilman Pfau both of the University of Stuttgart, Germany, have carried out charge-transport experiments with a single ion traversing a Bose-Einstein condensate (BEC), which is a quantum gas of cold neutral atoms [1]. The precise tracking of the ion shows that the transport is diffusive and reveals the character of the ion-atom collisions.

Martinus J.G. Veltman, a Dutch theoretical physicist who was awarded the Nobel Prize for work that explained the structure of some of the fundamental forces in the universe, helping to lay the groundwork for the development of the Standard Model, the backbone of quantum physics, died on Jan. 4 in Bilthoven, the Netherlands. He was 89.

His death was announced by the National Institute for Subatomic Physics in the Netherlands. No cause was given.

There are four known fundamental forces in the universe: gravity, electromagnetism, the strong force that bonds subatomic particles together, and the weak force that is responsible for particle decay. Since the discovery of the last two forces in the first half of the 20th century, physicists have looked for a unified theory that could account for the existence of all four.

A team of researchers affiliated with several institutions in China has used drones to create a prototype of a small airborne quantum network. In their paper published in the journal Physical Review Letters, the researchers describe sending entangled particles from one drone to another and from a drone to the ground.

Computer scientists, physicists and engineers have been working over the last several years toward building a usable quantum network —doing so would involve sending entangled particles between users and the result would be the most secure network ever made. As part of that effort, researchers have sent entangled particles over fiber cables, between towers and even from satellites to the ground. In this new effort, the researchers have added a new element—drones.

To build a long-range quantum network, satellites appear to be the ideal solution. But for smaller networks, such as for communications between users in the same city, another option is needed. While towers can be of some use, they are subject to weather and blockage, intentional or otherwise. To get around this problem, the researchers used drones to carry the signals.

Scientists at the Institute of Physics of the University of Tartu have found a way to develop optical quantum computers of a new type. Central to the discovery are rare earth ions that have certain characteristics and can act as quantum bits. These would give quantum computers ultrafast computation speed and better reliability compared to earlier solutions. The University of Tartu researchers Vladimir Hizhnyakov, Vadim Boltrushko, Helle Kaasik and Yurii Orlovskii published the results of their research in the scientific journal Optics Communications.

While in ordinary computers, the units of information are binary digits or bits, in quantum computers the units are quantum bits or qubits. In an ordinary computer, information is mostly carried by electricity in memory storage cells consisting of field-effect transistors, but in a quantum computer, depending on the type of computer, the information carriers are much smaller particles, for example ions, photons and electrons. The qubit information may be carried by a certain characteristic of this particle (for example, spin of electron or polarization of photon), which may have two states. While the values of an ordinary bit are 0 or 1, also intermediate variants of these values are possible in the quantum bit. The intermediate state is called the superposition. This property gives quantum computers the ability to solve tasks, which ordinary computers are unable to perform within reasonable time.