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Category: quantum physics – Page 3

Scientists advance quantum signaling with twisted light technology

A tiny device that entangles light and electrons without super-cooling could revolutionize quantum tech in cryptography, computing, and AI.

Present-day quantum computers are big, expensive, and impractical, operating at temperatures near-459 degrees Fahrenheit, or “absolute zero.” In a new paper, however, materials scientists at Stanford University introduce a new nanoscale optical device that works at room temperature to entangle the spin of photons (particles of light) and electrons to achieve quantum communication—an approach that uses the laws of quantum physics to transmit and process data. The technology could usher in a new era of low-cost, low-energy quantum components able to communicate over great distances.

“The material in question is not really new, but the way we use it is,” says Jennifer Dionne, a professor of materials science and engineering and senior author of the paper just published in Nature Communications describing the novel device. “It provides a very versatile, stable spin connection between electrons and photons that is the theoretical basis of quantum communication. Typically, however, the electrons lose their spin too quickly to be useful.”

Synchrotron radiation sources: Toolboxes for quantum technologies

Synchrotron radiation sources generate highly brilliant light pulses, ranging from infrared to hard X-rays, which can be used to gain deep insights into complex materials.

An international team has published an overview of synchrotron methods for the further development of quantum materials and technologies in the journal Advanced Functional Materials.

Using concrete examples, they show how these unique tools can help to unlock the potential of quantum technologies such as quantum computing, overcome production barriers and pave the way for future breakthroughs.

Scientists Teleport Entanglement Across Two Linked Quantum Networks in Historic First

Researchers at Heriot-Watt University have introduced a prototype quantum network that merges two smaller networks into a single, reconfigurable eight-user system capable of routing — and even teleporting — entanglement on demand. For many years, physicists have imagined a quantum internet: a glo

Single-photon teleportation achieved between distant quantum dots for the first time

An international research team involving Paderborn University has achieved a crucial breakthrough on the road to a quantum internet. For the first time ever, the polarization state of a single photon emitted from a quantum dot was successfully teleported to another physically separated quantum dot.

This means that the properties of one photon can be transmitted to another via teleportation. This is a particularly vital step for future quantum communication networks. For example, the scientists used a 270m free-space optical link for their experiments. The results have now been published in the journal Nature Communications.

Detecting strong-to-weak symmetry breaking might be impossible, study shows

When a system undergoes a transformation, yet an underlying physical property remains unchanged, this property is referred to as “symmetry.” Spontaneous symmetry breaking (SSB) occurs when a system breaks out of this symmetry when it is most stable or in its lowest-possible energy state.

Recently, physicists realized that a new type of SSB can occur in open quantum systems, systems driven by quantum mechanical effects that can exchange information, energy or particles with their surrounding environment. Specifically, they realized that the symmetry in these systems can be “strong” or “weak.”

A strong symmetry entails that both the open system and its surrounding environment individually obey the symmetry. In contrast, a weak symmetry takes place when the system and the environment only follow a symmetry when they are taken together.

On-demand electronic switching of topology achieved in a single crystal

University of British Columbia (UBC) scientists have demonstrated a reversible way to switch the topological state of a quantum material using mechanisms compatible with modern electronic devices. Published in Nature Materials, the study offers a new route toward more energy efficient electronics based on topologically protected currents rather than conventional charge flow.

“Conventional electronics involve currents of electrons that waste energy and generate heat due to electrical resistance. Topological currents are protected by symmetry, and so they are promising for new types of electronics with significantly less dissipation,” said Dr. Meigan Aronson, an investigator with UBC’s Stewart Blusson Quantum Matter Institute and the Department of Physics and Astronomy.

“Our research uncovers a specific mechanism where the addition or subtraction of electrical charge can drive a reversible topological transition in the crystal, switching it from a metal that can conduct charge to an insulator that can’t. This is a key step towards the implementation of a new type of low-dissipation electronics based on symmetry and topology, and not simply on charge.”

Controlling quantum states in germanene using only an electric field

Researchers at the University of Twente and Utrecht University demonstrated for the first time that quantum states in the ultra-narrow material germanene can be switched on and off using only an electric field. The researchers were able to vary the electric field strength very precisely, causing the special ‘topological’ states in nanoribbons to disappear or appear.

The research, titled “Electric-Field Control of Zero-Dimensional Topological States in Ultranarrow Germanene Nanoribbons,” is published in Physical Review Letters.

Quantum computers will not use zeros and ones, but instead use quantum bits that can assume both states simultaneously. In theory, this makes them superfast and powerful, but in practice, building quantum bits is an enormous challenge: they are very sensitive to noise and quickly lose their information.

Calibrating qubit charge to make quantum computers even more reliable

Quantum computers will be able to assume highly complex tasks in the future. With superconducting quantum processors, however, it has thus far been difficult to read out experimental results because measurements can cause interfering quantum state transitions.

Researchers at Karlsruhe Institute of Technology (KIT) and Université de Sherbrooke in Québec have performed experiments that improve our understanding of these processes and have shown that calibrating the charge at the qubits contributes to fault avoidance.

Their findings have been published in Physical Review Letters.

Noise-proof quantum sensor uses three calcium ions held in place by electric fields

Researchers at the University of Innsbruck have shown that quantum sensors can remain highly accurate even in extremely noisy conditions. It’s the first experimental realization of a powerful quantum sensing protocol, outperforming all comparable classical strategies—even under overwhelming noise.

The study has been published in Physical Review Letters.

Quantum sensors promise unprecedented measurement precision, but their advantage can quickly erode in realistic environments where noise dominates.

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