In 1987, I was a postdoctoral researcher on the hunt for a permanent job in physics. So of course, I made a point to attend the American Physical Society (APS) March Meeting, where every year physicists who study solids (or condensed matter) gather to report on their experiments, compare notes and geek out on the latest breakthroughs.
That year, the biggest breakthrough by far was high-temperature superconductivity.
Ring a bell? It well might. After all, it made the cover of Time magazine that spring, earned its discoverers a Nobel Prize the following fall. Unlike astrophysics and particle physics, it is not so common for our specialty to make headlines. We condensed matter scientists basked in the spotlight.
But it faded fast: The revolution didn’t happen, and science reporters moved on to dark matter, the Higgs boson and colliding black holes.
Well, it is time to pay attention again. Some of us science soldiers never stopped working on high-temperature superconductivity, and now we have something to show for it.
But I’m getting ahead of myself. First, let me finish the story of the physics conference heard round the world.
THE WOODSTOCK OF PHYSICS
In the year prior to that 1987 APS meeting, Georg Bednorz and Alex Müller had published news of a novel kind of superconductor—a material that conducts electricity with perfect efficiency. Superconductors had been around for decades at that point. Unfortunately, they operated only at temperatures so low you needed pricey liquid helium to create the effect, severely limiting their applications. Bednorz and Müller, however, had discovered a superconductor that worked in much warmer (or rather, less frigid) environments. Then, in February of 1987, other researchers had discovered a related material with superconductivity that was attainable using cheap liquid nitrogen as a coolant.
These thrilling findings inspired many physicists to join the hunt for the next great “high-temperature superconductor” (HTS). With HTS fever running rampant, the APS organized a special session on the topic at the March meeting.
I arrived an hour early, only to find some 2,000 scientists waiting in the corridors as if for the start of a Rolling Stones concert—except that everyone was sober. I was lucky enough to snag a seat near the rear of the conference hall, but hundreds of others had to watch on monitors outside.
That session, now known as the “Woodstock of Physics,” lasted until the small hours of the morning, the temperature in the room climbing as one scientist after another shared their findings. Craning to read each slide, we practically levitated on the wave of optimism as presenters talked of the game-changing technologies that would soon result from these astonishing materials. “The world has changed,” more than one speaker said, which is not the sort of language usually employed at staid physics meetings.
Turns out they were only half right.
Yes, the materials were remarkable. But for decades after that heady gathering, the HTS technology revolution remained as elusive as the world peace that was supposed to result from the original Woodstock. Many condensed matter physicists abandoned the HTS field for newer hot topics, like graphene and topological materials.
Over the decades, I have observed the ebb and flow of HTS research and done quite a bit myself, including at the National High Magnetic Field Laboratory (the MagLab), the site of a lot of that ebbing and flowing. I am now the lab’s director—a little older, a little wiser and a lot more clear-eyed about proclamations that The World Has Changed.
So it is as a seasoned skeptic that I say that the HTS technology era is finally here—for real.
The proof: We have built and will soon make available to scientists a superconducting magnet, made in part with HTS materials, that is a third stronger than any other superconducting magnet in the world. And this month in Nature, our scientists shared news of a test magnet that, using the same material and some very clever engineering, reached a world-record magnetic field that is promising for a host of applications, including still stronger research magnets. Also at the MagLab, we are in the midst of a multimillion dollar, National Science Foundation–funded project to design those still-stronger magnets.
It has been a slog, for sure. But in science, overnight revolutions happen about as often as researchers exclaim, “Eureka!” (Pro Tip: We hardly ever exclaim “Eureka!”). In their excitement about the scientific breakthroughs, HTS pioneers failed to foresee the many technical and economic hurdles ahead—like what it takes to turn a new superconductor into a wire.
Most HTS materials—REBCO (rare earth barium copper oxide), for example, or BSCCO (bismuth strontium calcium copper oxide)—consist of several elements that must be painstakingly measured, mixed and baked into a high-quality form. None of them are malleable, like copper. Instead, they are brittle, because they are ceramics. Imagine transforming a beautiful piece of REBCO pottery into a tape of perfectly aligned crystals, then spooling that into a coil to make an electromagnet. It was a Rumplestiltskin-scale challenge. But unlike Rumplestiltskin, it took us a couple of decades just to figure that part out.
Given such obstacles, the question should not be “What took you scientists and engineers so long to make HTS magnets?” but rather “How did you do that so fast!?”
SUPERCONDUCTORS ARE CHANGING THE WORLD
New materials pave the way (sometimes literally) for new eras. The discovery of bronze sparked profound changes in trade, government, agriculture, civilization and warfare. An advance in asphalt production in the late 19th century led to the paving of many of the world’s roads. Steel made it possible for buildings to soar more than a quarter mile into the sky. Plastics? Imagine modern life without them. Or modern technology without silicon.
The story line is the same in superconductivity, as new materials lead to ever more powerful magnets. (Magnetic fields are measured in teslas, with a fridge magnet having a field of about 0.01 tesla). In the early 1960s, the discovery of niobium-titanium boosted superconducting magnets to 10 teslas, enabling their use in everything from MRI machines to particle accelerators. In the mid 1970s, scientists discovered that niobium mixed with tin was an even better superconductor, leading to magnets of 24 teslas, now used for research at hundreds of universities.
With HTS, we are in the midst of writing the next chapter in this story. We know that REBCO, which can carry extremely high amounts of electricity, could theoretically generate 100 teslas. One day, it could be the stuff that makes the magnet equivalent of the Empire State Building.
I may have gotten a bit tipsy with overoptimism in that warm conference hall decades back. But these days, I base more sober predictions on experimental evidence, experience and peer-reviewed publications. Such as: HTS technology, in magnets and beyond, will bring about life-changing improvements in materials, medicine and energy.
New materials bring new technologies: your smartphone contains more than a dozen materials that were not yet invented at the time of the Woodstock meeting. Today, a single layer of carbon atoms arranged in a honeycomb pattern, called graphene, is showing promise for building ultrafast electronics. Two stacked layers of graphene might one day form the heart of a quantum computer. Other atomically thin materials are expected to soon outperform today’s silicon solar cells. And powerful magnets are one tool that scientists use to build an understanding of these new materials.
HTS magnets will power high-definition MRIs that will make today’s scans look like aged daguerreotypes, bringing into focus individual nerve fibers and cells. Unlike today’s MRIs, which locate only the hydrogen in your body to map of your innards, future HTS-based machines will allow doctors to image any of the elements in your body. They will image sodium to learn if chemotherapy is successfully killing tumor cells, and oxygen to track glucose metabolism in tumors, offering a safer alternative to PET scans. These machines will reveal the intricate structures of the cell walls of viruses so that scientists can design and deploy molecular missiles to infiltrate them.
These next-generation instruments will map more elements outside the body, as well. They will track lithium in batteries, hydrogen in fuel cells and photosynthesis in plants, giving scientists clues on how to build better solar cells and energy storage devices.
So, when exactly will all this occur?
I’m not gonna fall for that one again.