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Physicists push superconducting diodes to high temperatures

For the first time, researchers in China have demonstrated a high-temperature superconducting diode effect, which allows a supercurrent to flow in both directions. Published in Nature Physics, the team’s result could help address the noisy signals that pose a fundamental challenge in quantum computing.

A diode is a device that shows an asymmetric electrical response, allowing current to flow more easily in one direction than the other. Until recently, diode behavior had only been observed in conventional, non-superconducting electrical systems—but in 2020, a team of researchers in Japan became the first to demonstrate the diode effect in a superconductor. Ever since, this effect has gained increasing attention for its potential in practical quantum computing.

“However, most of the reported superconducting diodes work at low temperatures around 10 Kelvin, and often require an external magnetic field,” explains Ding Zhang at Tsinghua University and the Beijing Academy of Quantum Information Sciences, who led the research. “The diode efficiency is also low for many superconducting diodes.”

Shortest light pulse ever created captures ultrafast electron dynamics

Electrons determine everything: how chemical reactions unfold, how materials conduct electricity, how biological molecules transfer energy, and how quantum technologies operate. But electron dynamics happens on attosecond timescales—far too fast for conventional measurement tools.

Researchers have now generated a 19.2-attosecond soft X-ray pulse, which effectively creates a camera capable of capturing these elusive dynamics in real time with unprecedented detail, enabling the observation of processes never observed before. Dr. Fernando Ardana-Lamas, Dr. Seth L. Cousin, Juliette Lignieres, and ICREA Prof. Jens Biegert, at ICFO, has published this new record in Ultrafast Science. At just 19.2 attoseconds long, it is the shortest and brightest soft X-ray pulse ever produced, giving rise to the fastest “camera” in existence.

Flashes of light in the soft X-ray spectral range provide fingerprinting identification, allowing scientists to track how electrons reorganize around specific atoms during reactions or phase transitions. Generating an isolated pulse this short, required innovations in high-harmonic generation, advanced laser engineering, and attosecond metrology. Together, these developments allow researchers to observe electron dynamics, which define material properties, at their natural timescales.

Conventional entanglement can have thousands of hidden topologies in high dimensions

Researchers from the University of the Witwatersrand in South Africa, in collaboration with Huzhou University, discovered that the entanglement workhorse of most quantum optics laboratories can have hidden topologies, reporting the highest ever observed in any system: 48 dimensions with over 17,000 topological signatures, an enormous alphabet for encoding robust quantum information.

Most quantum optics laboratories produce entangled photons by a process of spontaneous parametric downconversion (SPDC), which naturally produces entanglement in “space,” the spatial degrees of freedom of light. Now the team have found that hidden in this space is a world of high-dimensional topologies, offering new paradigms for encoding information and making quantum information immune to noise. The topology was shown using the orbital angular momentum (OAM) of light, from two dimensional to very high dimensions.

Reporting in Nature Communications, the team showed that if one measures the OAM of two entangled photons it can be shown to have a topology: an underlying feature of the entanglement itself. Since OAM can take on an infinite number of possibilities, so too can the topology.

Everything in the universe is a quantum wave

A radical new interpretation of quantum mechanics is offered here. Professor of Quantum Information Science at the University of Oxford, Vlatko Vedral, argues that everything in the universe is a quantum wave. The difficulty of uniting the classical world and the quantum world is overcome; everything is quantum, and the quantum gives rise to the classical. His theory also overcomes the measurement problem, the observer problem, and the problem of quantum entanglement (spooky action at a distance). Poof goes the classical world!

There are, I believe, two main reasons why physics seems stuck at present. The last revolution was quantum mechanics and it began with Heisenberg’s famous paper exactly 100 years ago. And since then, not a single experiment has challenged the quantum description of reality. Not one. The first reason for this century-long absence of a new fundamental theory is that we simply haven’t had the appropriate experimental technology to probe regions where something could go wrong. This has now changed rapidly with the ongoing worldwide race to build a universal quantum computer. The technologies that go into this enterprise and that are being pursued by all the major industrial players are becoming sophisticated enough to test fundamental physics in a non-trivial way. However, there is a second reason for being stuck. It is the fact that we still haven’t agreed on the way to understand quantum mechanics. It is for this reason that I’d like to offer my own interpretation.

Laser light and the quantum nature of gravity: Proposed experiment could measure graviton energy exchange

When two black holes merge or two neutron stars collide, gravitational waves can be generated. They spread at the speed of light and cause tiny distortions in space-time. Albert Einstein predicted their existence, and the first direct experimental observation dates from 2015.

Now, Prof. Ralf Schützhold, theoretical physicist at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), is going one step further. He has conceived an experiment through which gravitational waves can not only be observed but even manipulated. Published in the journal Physical Review Letters, the idea could also deliver new insights into the hitherto only conjectured quantum nature of gravity.

“Gravity affects everything, including light,” says Schützhold. And this interaction also occurs when gravitational waves and light waves meet.

Sensor uses acoustic waves to detect objects at smallest scales

At the heart of every camera is a sensor, whether that sensor is a collection of light-detecting pixels or a strip of 35-millimeter film. But what happens when you want to take a picture of something so small that the sensor itself has to shrink down to sizes that cause the sensor’s performance to crater?

Now, Northeastern University researchers have made a breakthrough discovery in sensing technologies that allows them to detect objects as small as individual proteins or single cancer cells, without the additional need to scale down the sensor. Their breakthrough uses guided acoustic waves and specialized states of matter to achieve great precision within very small parameters.

The device, which is about the size of a belt buckle, opens up possibilities for sensing at both the nano and quantum scales, with repercussions for everything from quantum computing to precision medicine.

The mind-bending reality of quantum mechanics — with Jim Al Khalili

Jim Al-Khalili explores emerging technologies powering the future of quantum, and looks at how we got here.

This Discourse was recorded at the Ri on 7 November 2025, in partnership with the Institute of Physics.

Watch the Q&A session for this talk here (exclusively for our Science Supporter members):
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Physicist and renowned broadcaster Jim Al-Khalili takes a look back at a century of quantum mechanics, the strangest yet most successful theory in all of science, and how it has shaped our world. He also looks forward to the exciting new world of Quantum 2.0 and how a deeper understanding of such counterintuitive concepts as quantum superposition and quantum entanglement is leading to the development of entirely new technologies, from quantum computers and quantum sensors to quantum cryptography and the quantum internet.

The United Nations has proclaimed 2025 as the International Year of Quantum Science and Technology, to celebrate the centenary of quantum mechanics and the revolutionary work of the likes of Werner Heisenberg and Erwin Schrödinger. Together with the Institute of Physics, join us to celebrate the culmination of the International Year of Quantum at the penultimate Discourse of our Discover200 year.

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