In 1911, Dutch physicist Heike Kamerlingh Onnes made a paradigm-shifting discovery: at a few degrees above absolute zero, mercury completely lost its electrical resistance. This meant that with the right conditions, electrical currents could travel indefinitely without losing power as it passed through matter.
Scientists soon realized that this feature, dubbed superconductivity, wasn’t just limited to mercury. Specific quantum mechanical effects enable superconductivity, so other elements could exhibit these properties under the right conditions. Eventually, physicists found a way to bring superconducting materials into wires and magnets, which opened up entirely new avenues for testing and utilizing weird quantum phenomena. For instance, our best quantum computers and particle accelerators rely on superconducting materials to operate. You don’t even have to be a physicist to have been close to one if you’ve ever taken an MRI.
Unfortunately, superconductors still require incredibly low temperatures to function, which complicates things. For example, in the case of quantum computers, noise reduction and error correction remain a major hurdle requiring near-zero Kelvin temperatures for their qubits.
Naturally, scientists want to ramp up the temperature threshold for superconductors—to develop “room-temperature” superconductors, so to speak. The jury’s still out on whether that’s at all feasible. But researchers have been hard at work finding new combinations and designs to coax superconductors into warmer and warmer conditions. And, they’ve made some progress to that end.
For this Giz Asks, we asked researchers for a breakdown of the status quo. What kind of progress has the community made in recent times? What are some promising candidates for room-temperature (or somewhere in that regime) superconductors? What are some remaining challenges for researchers, and how are they addressing them? The following responses may have been slightly edited for length and clarity.
Hanyu Liu
Physicist, Key Laboratory of Material Simulation Methods and Software of Ministry of Education; Jilin University, China.
Over the past decade, superconductor research has seen major progress, mostly driven by the booming study of hydride superconductors under high pressure. Even so, practical room-temperature superconductors are still far from reality. Most of these hydride materials only work under enormous pressure, way higher than normal atmospheric pressure, which makes them for everyday use unlikely.
There are also some promising but less well-known candidates, including boron-based compounds and newly discovered hydrides that work at relatively lower pressures. We are unlikely to get an ambient-pressure, room-temperature superconductor for consumer electronics in the next 10 to 15 years. What we will probably see sooner is wider use of nitrogen-cooled high-temperature superconductors for power grids and specialized equipment, not home appliances.
Liangzi Deng and Paul C. W. Chu
Physicists, University of Houston (UH). Deng and Chu contributed to recent work published in the Proceedings of the National Academy of Sciences (PNAS) that set a new record for superconductivity at ambient pressure.
The good news is that we are getting closer, but “practical” means more than simply achieving a high superconducting transition temperature (Tc). The first superconductor (YBCO) with a Tc (93 K) above the boiling point of liquid nitrogen (77 K) was discovered by Chu and his colleagues in 1987. For many years, some of the highest superconducting temperatures have been reached only under enormous pressures, which makes those states extremely difficult to use outside specialized laboratories. A potentially important change is to think of pressure not as a condition that must be maintained forever, but as a processing tool—use pressure to create a desirable state, then find a way to keep that state after the pressure is removed.
That is the idea behind the recently developed pressure-quench protocol on superconductors, led by our team at UH. The approach has already retained pressure-enhanced superconductivity in FeSe at ambient pressure, followed by pressure-induced superconducting phases in other materials such as Bi0.5Sb1.5Te3. More recently, pressure quenching raised the ambient-pressure superconducting Tc of HgBa₂Ca₃Cu₃O₈+δ to 151 K, surpassing the previous ambient-pressure record of 133 K that had stood for more than three decades.
That does not mean practical superconducting power cables or electronics based on pressure-quenched materials are around the corner. The next challenges are substantial: making the retained states more thermally and temporally stable, understanding what actually stabilizes them, increasing the sample size, demonstrating reproducible processing, and ultimately showing useful critical currents in forms such as wires, tapes, or films. But pressure quenching changes the question in an interesting way. Instead of asking only, “How high can Tc go under pressure?” we can now also ask, “Can we bring the properties created by pressure back with us?” If that strategy proves general and scalable, it could significantly narrow the gap between spectacular high-pressure discoveries and superconductors that can actually be used.
Zi-Kui Liu
Materials scientist, Pennsylvania State University.
Superconductivity has made remarkable progress, including demonstrations of very high transition temperatures in hydrogen-rich materials under extremely high pressures. However, I would be cautious about predicting when a room-temperature or near-room-temperature superconductor will become a practical technology. A high Tc by itself is not sufficient: a useful material must also be stable at or near ambient pressure, carry substantial electrical currents and magnetic fields, be mechanically robust, manufacturable at scale, and economically viable. At present, I don’t think we know of a material that simultaneously satisfies these requirements, so I would not put a reliable timeline on practical consumer superconductors.
An important direction, in my view, is to understand not simply how to create a superconducting state, but how the atomic and electronic structure can protect that state against thermal fluctuations. In our recent work, we proposed a symmetry-broken superconducting configuration (SCC) and identified straight one-dimensional tunnels (SODTs) in the charge-density difference between superconducting and normal configurations. We found these features in both conventional and unconventional superconductors, including YBCO. In YBCO, we proposed that a layered “pontoon” structure, with relatively weak bonding between the superconducting layers and the surrounding bulk, helps protect these superconductivity-related electronic structures against thermal disruption and thereby contributes to its relatively high TC.
We have also filed a provisional patent application, “Method for Identifying and Predicting Superconductivity Based on Symmetry-Broken Charge Density Tunnels and Pontoon Structures.” We are now working toward extending this framework to understand the thermodynamic stability of these configurations at finite temperature using our Zentropy theory and, ultimately, to use it for the prediction and design of new superconducting materials.
Matt Julian and Rohit Prasankumar
Enterprise Science Fund, Intellectual Ventures. Along with Deng and Chu, Julian and Prasankumar co-authored the PNAS paper that set a new record for superconductivity in ambient pressures. Intellectual Ventures was a funder of the project.
A room-temperature, ambient-pressure superconductor is arguably the greatest unsolved challenge in condensed matter physics, with the potential to transform society on the scale of the Internet or artificial intelligence. We are quite optimistic that despite recent discredited claims and ongoing controversy, we are closer than ever before to realizing practical, commercializable superconducting materials for such applications. Our understanding of superconductivity is deeper than ever, and the tools available to apply it—from advanced fabrication techniques to GPU-accelerated first-principles simulations—have never been more powerful. Yet of course, understanding and capability alone will not get us there.
It is tempting to treat prediction as the destination: if we can computationally identify a candidate material, by either intricate physics-laden first principles calculations or brute force statistical methods, success feels within reach. But predicting a superconducting material is not enough. We must predict superconductors that can actually be synthesized and, harder still, synthesize what we predict. We must also develop methods to predictively enhance superconductivity through deliberate engineering of structural and electronic characteristics that govern superconducting behavior. Harnessing materials that exhibit unconventional superconductivity will also be a critical piece in reaching room temperature. There is a great deal of nuance, complexity, and challenging synthesis work that goes into each of these objectives. Meeting them will require human creativity drawn from many different scientific traditions working in genuine concert.
Moving from discovery of a high-temperature superconductor to discovery of a practical high-temperature superconductor comes with significant further complexity. A practical material will need to be drawn into wires or tapes and wound, or be deposited as a film or coating, or be compatible with semiconductor foundry processes. Each of these has different critical material properties, and there are significant challenges in accurately modeling these for truly new materials. We therefore need to overcome the challenge of computationally screening for “practicality” to avoid the need for a massive number of complex experiments. We then need to find ways to avoid the traditional 20-year development cycle between material discovery and commercial adoption.
Our path forward is a tightly integrated, multidisciplinary approach that brings condensed matter physicists, chemists, materials scientists, experimentalists, theorists, and computational engineers in close collaboration. We must reach across disciplinary boundaries, exchange knowledge, and build shared frameworks to unravel not only those challenges we already understand but also those that remain elusive. We do know more than ever, but there is so much yet to learn. The opportunity is vast, and this uncertainty is in fact the clearest indication that the greatest discoveries in this field still lie ahead.
Giz Asks is a recurring Gizmodo series in which experts answer big questions in their own words, offering a range of perspectives on the ideas, discoveries, and debates that affect our lives and shape our understanding of the world.
