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Unraveling the mystery of high-temperature superconductors from first principles

Ever since their discovery almost four decades ago, high-temperature superconductors have fascinated scientists and engineers alike. These materials, primarily cuprates, defy classical understanding because they conduct electricity without resistance at temperatures far higher than traditional superconductors. Yet despite decades of research, we still don’t have a clear, comprehensive microscopic picture of how superconductivity emerges in these complex materials.

During my Ph.D. at Caltech, I was intrigued by the profound puzzle presented by high-temperature superconductors: Can we directly compute their from fundamental quantum mechanics without relying on simplified models or approximations? With this question, I embarked on a challenging but rewarding scientific journey.

Quantum tornadoes in momentum space: First experimental proof of a new quantum phenomenon

Researchers from Würzburg have experimentally demonstrated a quantum tornado for the first time by refining an established method. In the quantum semimetal tantalum arsenide (TaAs), electrons in momentum space behave like a swirling vortex. This quantum phenomenon was first predicted eight years ago by a Dresden-based founding member of the Cluster of Excellence ct.qmat.

The discovery, a collaborative effort between ct.qmat, the research network of the Universities of Würzburg and Dresden, and international partners, has now been published in Physical Review X.

Scientists have long known that electrons can form vortices in quantum materials. What’s new is the proof that these tiny particles create tornado-like structures in momentum space—a finding that has now been confirmed experimentally. This achievement was led by Dr. Maximilian Ünzelmann, a group leader at ct.qmat—Complexity and Topology in Quantum Matter—at the Universities of Würzburg and Dresden.

Metasurface technology offers a compact way to generate multiphoton entanglement

Quantum information processing is a field that relies on the entanglement of multiple photons to process vast amounts of information. However, creating multiphoton entanglement is a challenging task. Traditional methods either use quantum nonlinear optical processes, which are inefficient for large numbers of photons, or linear beam-splitting and quantum interference, which require complex setups prone to issues like loss and crosstalk.

A team of researchers from Peking University, Southern University of Science and Technology, and the University of Science and Technology of China have made a significant breakthrough in this area.

As reported in Advanced Photonics Nexus, they developed a new approach using metasurfaces, which are planar structures capable of controlling various aspects of light, such as phase, frequency, and polarization. This innovative approach allows for the generation of multiphoton entanglement on a single , simplifying the process while making it more efficient.

New Photon Entanglement Breakthrough Could Miniaturize Quantum Computers

Quantum computing has long struggled with creating entangled photons efficiently, but a team of researchers has discovered a game-changing method using metasurfaces—flat, engineered structures that control light.

By leveraging these metasurfaces, they can generate and manipulate entangled photons more easily and compactly than ever before. This breakthrough could open the door to smaller, more powerful quantum computers and even pave the way for quantum networks that deliver entangled photons to multiple users.

Revolutionizing Quantum Information Processing.

New equation links Einstein’s relativity, quantum theory with entropy

Physicists have long attempted to find a single theory that unites quantum mechanics and general relativity.

This has been very tricky because quantum mechanics focuses on the unpredictable nature of particles at microscopic scales, whereas general relativity explains gravity as the curvature of spacetime caused by massive objects.

The two theories discuss forces existing on different scales. Bianconi employed an interesting approach to deal with this challenge. She proposes an entropic action where, instead of being a fixed background, spacetime works like a quantum operator — acting on quantum states and deciding how they change over time.

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