Triggering room-temperature superconductivity with light

Scientists discover that triggering superconductivity with a flash of light involves the same fundamental physics that are at work in the more stable states needed for devices, opening a new path toward producing room-temperature superconductivity.

Much like people can learn more about themselves by stepping outside of their comfort zones, researchers can learn more about a system by giving it a jolt that makes it a little unstable – scientists call this “out of equilibrium” – and watching what happens as it settles back down into a more stable state.

In the case of a superconducting material known as yttrium barium copper oxide, or YBCO, experiments have shown that under certain conditions, knocking it out of equilibrium with a laser pulse allows it to superconduct – conduct electrical current with no loss – at much closer to room temperature than researchers expected. This could be a big deal, given that scientists have been pursuing room-temperature superconductors for more than three decades.

But do observations of this unstable state have any bearing on how high-temperature superconductors would work in the real world, where applications like power lines, maglev trains, particle accelerators and medical equipment require them to be stable?

A study published in Science Advances today suggests that the answer is yes.

“People thought that even though this type of study was useful, it was not very promising for future applications,” said Jun-Sik Lee, a staff scientist at the Department of Energy’s SLAC National Accelerator Laboratory and leader of the international research team that carried out the study.

Read more on the SLAC website

Image: To study superconducting materials in their “normal,” non-superconducting state, scientists usually switch off superconductivity by exposing the material to a magnetic field, left. SLAC scientists discovered that turning off superconductivity with a flash of light, right, produces a normal state with very similar fundamental physics that is also unstable and can host brief flashes of room-temperature superconductivity. These results open a new path toward producing room-temperature superconductivity that’s stable enough for practical devices.

Credit: Greg Stewart/SLAC National Accelerator Laboratory

Nights!

Experimental time at light sources is very precious. When a synchrotron or X-ray Free Electron Laser (XFEL) is in operating mode the goal is to allocate as many experimental shifts to external scientists and in-house research as possible. This includes night shifts! So, how do light source users survive the night shifts? #LightSourceSelfies brings you top tips from scientists based at, or using, 5 light sources in our collaboration – the ESRF, Advanced Light Source (ALS), ANSTO’s Australian Synchrotron, CHESS and the PAL XFEL.

That 1st light source experiment: The best way to understand is to experience!

Sae Hwan Chun, beamline scientist and condensed matter physicist at the PAL XFEL

Sae Hwan Chun is a beamline scientist and condensed matter physicist at the PAL XFEL is South Korea, one of the seven XFEL facilities in the Lightsources.org collaboration. Sae Hwan is able to research ultra-fast and dynamic phenomena in condensed matter by using the femtosecond X-ray pulses that XFELs generate.

In his #LightSourceSelfie, recalling his first synchrotron experiment at the Advanced Photon Source (APS), Sae Hwan said, “I thought that I understood how to do the experiment, but actually doing it was a completely different matter. It was like even though you pass a written exam for a driving license your mind goes blind to when you actually drive a car for the first time. This first day gave me a lesson that you should experience something if you want to understand it.”

Collaboration: a watchword for the light source community

Scientists Nina Perry and Nina Vyas, from Diamond Light Source (https://diamond.ac.uk – the UK’s synchrotron), along with SaeHwan Chun, scientist at the PAL-XFEL (https://pal.postech.ac.kr/paleng/ – the Free Electron Laser in South Korea) talk about a theme that is common to all light sources around the world, and indeed to science and all its associated disciplines. Cooperation and collaboration, and their benefits for scientists’ wellbeing as well as the science, are highlighted in this #LightSourceSelfie video.

Nina Perry & Ninya Vyas, on Beamline B24 at Diamond Light Source, the UK’s synchrotron science facility

Beginning your light source journey

Scientists who use synchrotrons such as the Advanced Light Source in California and CHESS at Cornell University, along with staff scientists at Free Electron Lasers in South Korea (the PAL-XFEL) and California (LCLS at SLAC), reflect on how they felt the first time they used a light source facility to conduct research experiments.  The expertise available from the staff scientists who work on the beamlines is also highlighted in this #LightSourceSelfie video.