For the first time, researchers have been able to record, frame-by-frame, how an electron interacts with certain atomic vibrations in a solid. The technique captures a process that commonly causes electrical resistance in materials while, in others, can cause the exact opposite–the absence of resistance, or superconductivity.
“The way electrons interact with each other and their microscopic environment determines the properties of all solids,” said MengXing Na, a University of British Columbia (UBC) PhD student and co-lead author of the study, published in Science (“Direct determination of mode-projected electron-phonon coupling in the time domain”). “Once we identify the dominant microscopic interactions that define a material’s properties, we can find ways to ‘turn up’ or ‘down’ the interaction to elicit useful electronic properties.”
Controlling these interactions is important for the technological exploitation of quantum materials, including superconductors, which are used in MRI machines, high-speed magnetic levitation trains, and could one day revolutionize how energy is transported.
At tiny scales, atoms in all solids vibrate constantly. Collisions between an electron and an atom can be seen as a ‘scattering’ event between the electron and the vibration, called a phonon. The scattering can cause the electron to change both its direction and its energy. Such electron-phonon interactions lie at the heart of many exotic phases of matter, where materials display unique properties.
With the support of the Gordon and Betty Moore Foundation, the team at UBC’s Stewart Blusson Quantum Matter Institute (SBQMI) developed a new extreme-ultraviolet laser source to enable a technique called time-resolved photoemission spectroscopy for visualizing electron scattering processes at ultrafast timescales.

Image Credit:  UBC


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