It’s here: Scientists have reported the discovery of the first room-temperature superconductor, after more than a century of waiting. Physicist Ranga Dias at the University of Rochester in New York, along with Salamat and other collaborators discovered a superconductor that works at temperatures of about 15° Celsius (59° Fahrenheit).
15 October, 2020 | 03:00 a.m.
For decades, physicists have dreamed of discovering a material that could effortlessly convey electricity at everyday temperatures, a feat that would save gargantuan amounts of energy and revolutionize modern technology.
Now, scientists have found the first superconductor that operates at room temperature — at least given a fairly chilly room. The material is superconducting below temperatures of about 15° Celsius (59° Fahrenheit), physicist Ranga Dias of the University of Rochester in New York and colleagues report October 14 in Nature.
Developing materials that are superconducting—without electrical resistance and expulsion of magnetic field at room temperature—is the “holy grail” of condensed matter physics. Sought for more than a century, such materials “can definitely change the world as we know it - Ranga Dias
The discovery evokes daydreams of futuristic technologies that could reshape electronics and transportation. Superconductors transmit electricity without resistance, allowing current to flow without any energy loss. But all superconductors previously discovered must be cooled, many of them to very low temperatures, making them impractical for most uses.
The team’s results “are nothing short of beautiful,” says materials chemist Russell Hemley of the University of Illinois at Chicago, who was not involved with the research.
However, the new material’s superconducting superpowers appear only at extremely high pressures, limiting its practical usefulness.
The first superconductors observed by scientists lost their electrical resistance only at ultracold temperatures, a few degrees above absolute zero, or minus 459.67 degrees, the lowest possible temperature. In the 1980s, physicists discovered so-called high-temperature superconductors, but even those became superconducting at temperatures far more frigid than those encountered in everyday life.
Dr. Dias’s group looked at a mixture of three elements: hydrogen, sulfur and carbon. With three elements, the scientists were able to adjust the electronic properties to achieve higher superconducting temperatures.
“You can start with knowing what the good binary systems are and then potentially adding another element to it to get more complex,” said Eva Zurek, a professor of chemistry at the University at Buffalo who performs numerical calculations to predict the behaviour of the high-pressure materials. “And hopefully, this complexity can bring the superconducting critical temperature up or stabilization pressure down.”
Dr. Zurek, who was not involved with the latest research, said carbon was a good third element to add because it formed strong bonds that could potentially keep the material together. “If you release the pressure, then those bonds potentially will not break,” she said.
To make the superconductor, the scientists had to squeeze the substance between two diamonds to nearly 40 million pounds per square inch. That is approximately the pressure you’d experience if you could tunnel more than 3,000 miles into the Earth and arrived at the bottom of the molten iron outer core.
The process produced specks of material about the volume of a single inkjet particle.
The experimental results did not fully agree with Dr. Zurek’s computer calculations, which predicted the highest superconducting temperatures at lower pressures. Dr. Dias instead found that the superconducting temperature continued to increase as the pressure rose.
If a room-temperature superconductor could be used at atmospheric pressure, it could save vast amounts of energy lost to resistance in the electrical grid. And it could improve current technologies, from MRI machines to quantum computers to magnetically levitated trains. Dias envisions that humanity could become a “superconducting society.”
Developing materials that are superconducting—without electrical resistance and expulsion of the magnetic field at room temperature—is the “holy grail” of condensed matter physics. Sought for more than a century, such materials “can definitely change the world as we know it.