Phys.org July 6, 2022
To visualize electron vortices, an international team of researchers (Israel, USA – University of Colorado, MIT) synthesized pure single crystals of tungsten ditelluride, and exfoliated thin flakes of the material. Using e-beam lithography and plasma etching techniques they patterned each flake into a center channel connected to a circular chamber on either side. They etched the same pattern into thin flakes of gold with ordinary, classical electronic properties. They ran a current through each patterned sample at ultralow temperatures of 4.5 kelvins and measured the current flow at specific points throughout each sample, using SQUID on a tip. Scanning each sample they observed that the electrons flowing through patterned channels in gold flakes did so without reversing direction while the electrons flowing through tungsten ditelluride flowed through the channel and swirled into each side chamber creating small whirlpools in each chamber before flowing back out into the main channel. There was a change in the flow direction in the chambers, a clear signature of electrons being in a fluid-like regime. The findings represented an experimental confirmation of a fundamental property in electron behavior. They may also offer clues to how engineers might design low-power devices that conduct electricity in a more fluid, less resistive manner…read more. TECHNICAL ARTICLEÂ
Comparison between vorticity and vortical streamlines. Credit: Nature volume 607, pages 74–80 (2022)