A team of physicists at MIT has managed to do something long thought impossible: peer into the ultrafast, quantum-scale motion of superconducting electrons. Using a microscope built around pulses of terahertz light – radiation oscillating trillions of times per second – they've captured a kind of atomic dance that has remained hidden until now.
The implications of the breakthrough could ripple through multiple industries. A better understanding of how superconductivity behaves at quantum scales could accelerate the development of room-temperature superconductors, radically improving electrical grids, quantum computers, and magnetic levitation systems.
The underlying terahertz technology itself – capable of transmitting and detecting signals at unprecedented speeds – could shape the future of wireless communications, sensing devices, and ultrafast data transfer for next-generation electronics.
The development, described in Nature, centers on bismuth strontium calcium copper oxide (BSCCO), a copper-based superconductor known for carrying electricity without resistance at relatively high temperatures.
When hit with precisely tuned terahertz bursts, the electrons inside the material began to move collectively, vibrating in unison at the same frequencies as the light itself. MIT physicist Nuh Gedik calls this previously unseen motion "a new mode of superconducting electrons."
The feat was accomplished using a terahertz microscope capable of compressing radiation that typically stretches hundreds of microns long down to the tiny scale of a quantum material. Terahertz radiation sits between microwaves and infrared on the electromagnetic spectrum, an energy range considered a sweet spot for imaging because it's non-ionizing, penetrates deeply, and matches the natural oscillation rate of atoms and electrons.
Yet until now, it's been all but useless for imaging small structures because of a fundamental barrier called the diffraction limit – light can't be focused to a spot smaller than its own wavelength.
MIT postdoctoral researcher Alexander von Hoegen and colleagues found a way to beat that limitation. They used a spintronic emitter, a layered metallic structure that generates sharp terahertz pulses when hit by a laser.
By placing microscopic samples extremely close to this source, the researchers trapped the light before it could spread out, focusing the energy into a region much smaller than its wavelength. That confinement allowed the microscope to resolve features that had been invisible under conventional terahertz illumination.
The design integrates the emitter with a Bragg mirror – a stack of ultrathin reflective layers that filter unwanted light while allowing the desired terahertz frequencies through. This setup protects the fragile sample from the optical laser but preserves the high-frequency terahertz signals scientists want to study.
In their first experiment, the researchers cooled a BSCCO sample to near absolute zero, where it enters its superconducting phase. As terahertz pulses moved through the chilled material, detectors picked up faint oscillations in the returning field – a telltale sign that electrons inside were moving collectively like a frictionless fluid.
The team compared the signals to theoretical predictions and confirmed that they had, for the first time, imaged the quantum superfluid motion itself. "It's this superconducting gel that we're sort of seeing jiggle," von Hoegen explained.
The visualization offers a new window into the quantum dynamics of superconductors and could help uncover factors that might one day enable superconductivity at room temperature – a long-sought goal in physics and energy technology.
Von Hoegen sees broad implications beyond basic physics. Future terahertz microscopes, he said, could study signal propagation in nanoscale antennas or sensors designed for terahertz-frequency telecommunications – the next frontier beyond today's Wi-Fi and millimeter-wave systems.
"There's a huge push to take Wi-Fi or telecommunications to the next level, to terahertz frequencies," he said. "If you have a terahertz microscope, you could study how terahertz light interacts with microscopically small devices that could serve as future antennas or receivers."
With the new microscope now operational, the team plans to explore other two-dimensional materials known for exotic electronic behaviors, hoping to capture their internal vibrations in the terahertz domain. Each experiment, they say, brings them closer to understanding how electrons cooperate when friction disappears – and what that could mean for the future of electronic materials.
Reference:
"Imaging a terahertz superfluid plasmon in a two-dimensional superconductor" - A. von Hoegen, T. Tai, C. J. Allington, M. Yeung, J. Pettine, M. H. Michael, E. Viñas Boström, X. Cui, K. Torres, A. E. Kossak, B. Lee, G. S. D. Beach, G. D. Gu, A. Rubio, P. Kim & N. Gedik: DOI https://www.nature.com/articles/s41586-025-10082-2
(Score: 1, Interesting) by Anonymous Coward on Thursday February 12, @02:03PM (1 child)
Anyone understand this?
Got a car analogy??
(Score: 3, Funny) by Freeman on Thursday February 12, @04:16PM
Except instead of electricity it's light and instead of a movie, it's real science. Also is lacking 1 DeLorean which makes it a lot less interesting.
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"