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The agreement of the results is an impressive confirmation of the standard model of physics.

Quantum sensors can now detect signals of arbitrary frequencies thanks to a quantum version of frequency mixing—a widely used technique in electronics.

Monitoring the fissile material aboard nuclear-powered submarines is notoriously difficult. Researchers may now have a way to safeguard this weapons-grade substance.

Actually transporting quantum states over significant distances is tricky, though. Researchers have had some success transmitting messages tied up in the quantum states of photons over several hundred miles of optical cables, and also using satellite quantum communication to establish links over even greater distances. But the inevitable signal losses over either mode of communication mean that scaling up to the distances required for a true internet will be tricky.

One workaround is to exploit another quantum phenomenon called teleportation. This works much like the sci-fi concept used in shows like Star Trek, allowing information to be instantaneously transmitted from one place to another, theoretically over unlimited distances. And now, researchers from the Netherlands have provided the first practical demonstration of how this could work.

The team set up three quantum “nodes” called Alice, Bob, and Charlie, which are able to store quantum information in qubits—the quantum equivalent of bits in a computer made from nitrogen vacancy centers. These are tiny defects in diamonds that can be used to trap electrons and alter their quantum state. They then connected Alice to Bob and Bob to Charlie using optical fibers.

A new demonstration of these exotic constructs could help bridge classical and quantum physics.

Electrons are some of the most basic building components of matter that we are familiar with. They have several distinguishing characteristics, including a negative charge and the existence of an exact intrinsic angular momentum, often known as spin. Each electron, as a charged particle with spin, has a magnetic moment that aligns in a magnetic field as a compass needle does.

Quantum electrodynamics can forecast the strength of this magnetic moment, which is given by the so-called g-factor, with incredible accuracy. This computation agrees to within 12 digits with the empirically determined g-factor, making it one of the most precise theory-experiment matches in physics to date. The magnetic moment of the electron, on the other hand, changes when it is no longer a “free” particle, that is, when it is linked to an atomic nucleus, for example. QED, which defines the interaction between electrons and nucleus in photon exchange, can be used to determine minor changes in the g-factor. This notion can be sensitively tested thanks to high-precision measurements.

In a new study, scientists at the Max Planck Institute for Nuclear Physics (MPIK) in Heidelberg successfully investigated QED predictions with unprecedented resolution. They used a newly developed technique to measure a very small difference in the magnetic properties of two isotopes of highly charged neon in an ion trap with previously inaccessible accuracy.

Imagine a road with two lanes in each direction. One lane is for slow cars, and the other is for fast ones. For electrons moving along a quantum wire, researchers in Cambridge and Frankfurt have discovered that there are also two “lanes,” but electrons can take both at the same time!

Current in a wire is carried by the flow of electrons. When the wire is very narrow (one-dimensional, 1D) then electrons cannot overtake each other, as they strongly repel each other. Current, or energy, is carried instead by waves of compression as one particle pushes on the next.

It has long been known that there are two types of excitation for electrons, as in addition to their charge they have a property called spin. Spin and charge excitations travel at fixed, but different speeds, as predicted by the Tomonaga-Luttinger model many decades ago. However, theorists are unable to calculate what precisely happens beyond only small perturbations, as the interactions are too complex. The Cambridge team has measured these speeds as their energies are varied, and find that a very simple picture emerges (now published in the journal Science Advances). Each type of excitation can have low or high kinetic energy, like cars on a road, with the well-known formula E=1/2 mv², which is a parabola. But for spin and charge the masses m are different, and, since charges repel and so cannot occupy the same state as another charge, there is twice as wide a range of momentum for charge as for spin.

Researchers from the University of Nebraska-Lincoln and the University of California, Berkeley, have developed a new photonic device that could get scientists closer to the “holy grail” of finding the global minimum of mathematical formulations at room temperature. Finding that illusive mathematical value would be a major advancement in opening new options for simulations involving quantum materials.

Many scientific questions depend heavily on being able to find that mathematical value, said Wei Bao, Nebraska assistant professor of electrical and computer engineering. The search can be challenging even for modern computers, especially when the dimensions of the parameters—commonly used in quantum physics—are extremely large.

Until now, researchers could only do this with polariton optimization devices at extremely low temperatures, close to about minus 270 degrees Celsius. Bao said the Nebraska-UC Berkeley team “has found a way to combine the advantages of light and matter at room temperature suitable for this great optimization challenge.”

Stanene is a topological insulator comprised of atoms typically arranged in a similar pattern to those inside graphene. Stanene films have been found to be promising for the realization of numerous intriguing physics phases, including the quantum spin Hall phase and intrinsic superconductivity.

Some theoretical studies also suggested that these films could host topological superconductivity, a state that is particularly valuable for the development of quantum computing technology. So far, however, topological edge states in stanene had not been reliably and consistently observed in experimental settings.

Researchers at Shanghai Jiao Tong University, the University of Science and Technology of China, Henan University, Zhengzhou University, and other institutes in China have recently demonstrated the coexistence of topological edge states and superconductivity in one to five-layer stanene films placed on the Bi(111) substrate. Their observations, outlined in a paper published in Physical Review Letters, could have important implications for the development of Stanene-based quantum devices.

D-Wave opens up access to its next-generation 500 qubit quantum computer Advantage2.