For the first time, MIT researchers have observed “electron whirlpools.” When electricity flows as a fluid, strange behavior occurs, which could lead to more efficient electronics.

For the first time, scientists have discovered "electron whirlpools." MIT's Christine Daniloff
For the first time, scientists have discovered “electron whirlpools.” MIT’s Christine Daniloff

Because electricity, like water, is made up of discrete particles, one might expect them to flow similarly. However, unlike water molecules, which can jostle and flow together, electrons are much smaller, which means they are more influenced by their surroundings than by each other.

However, under ideal conditions – close to absolute zero temperatures and in pure, defect-free materials – quantum effects should take over their movement and allow them to flow as an electron fluid with the viscosity of honey. If scientists can harness this, it could lead to more efficient electronic devices with less resistance to electricity flow.

A diagram depicting electron flow in a standard metal (gold) on the left and electron whirlpools in a quantum material (tungsten ditelluride) on the rightMIT
A diagram depicting electron flow in a standard metal (gold) on the left and electron whirlpools in a quantum material (tungsten ditelluride) on the rightMIT

The MIT team discovered whirlpools as a clear sign of an electron fluid in their new study. These are common structures in fluid flows, but they are not typically produced by electrons, so they have never been observed before. The electron whirlpools were discovered in tungsten ditelluride crystals by the researchers.

“Tungsten ditelluride is one of the new quantum materials in which electrons interact strongly and behave as quantum waves rather than particles,” said co-author Leonid Levitov. “Moreover, the material is very clean, making the fluid-like behavior directly accessible.”

The team etched a narrow channel in this material with a circular chamber on either side, then ran a current through it and measured electron flow. Even when electrons spread out into the chambers and then returned to the central channel in standard materials like gold, they would always flow in the same general direction. However, electrons in the tungsten ditelluride swirled through the circular chambers, reversing direction and creating whirlpools.

“Electron vortices are expected in theory,” Levitov said, “but there has been no direct proof, and seeing is believing.” “We’ve seen it now, and it’s a clear indication that we’re in this new regime, where electrons behave as a fluid rather than as individual particles.”

The researchers etched a narrow channel in this material with a circular chamber on each side, then passed a current through it to measure electron flow. Even in standard materials like gold, electrons spread out into the chambers and then returned to the central channel in the same general direction. Electrons in the tungsten ditelluride, on the other hand, swirled through the circular chambers, reversing direction and creating whirlpools.

“Electron vortices are expected in theory,” Levitov said, “but no direct proof has been found, and seeing is believing.” “We’ve seen it now, and it’s a clear indication that we’ve entered a new regime in which electrons behave as a fluid rather than as individual particles.”

Source: MIT

Leave a Reply

Your email address will not be published.