Researchers at the Massachusetts Institute of Technology (MIT) have observed an "electron vortex" for the first time. 's strange, fluid-like electronic behavior could be used in the next generation of low-power electronics, potentially making them more efficient.
Although they are discrete particles, water molecules flow collectively as a liquid, creating streams, waves, eddies, and other classic fluid phenomena. While electric current is also a construct of different particles (in this case, electrons), the particles are so small that any collective behavior between them is overwhelmed by the larger effects as the electrons pass through ordinary metals. However, in certain materials and under certain conditions, this effect gradually disappears and the electrons can interact directly with each other. In these cases, electrons can flow collectively like a fluid.
It was predicted that under ideal conditions - at temperatures close to absolute zero and in pure, defect-free materials - quantum effects should take over their motion and allow them to flow as an electronic fluid, with honey-like properties viscosity. If scientists could take advantage of this, they could create more efficient electronic devices with less resistance to the flow of electricity.
In new research, an MIT team has observed a telltale sign of electron fluids - "whirlpools." These are common structures in fluids, but are not ones that electrons can typically create, so they have never been observed before. Researchers discovered "electron vortices" in crystals of tungsten ditelluride.
Leonid Levitov, co-author of the study, said: "Tungsten ditelluride is one of the new quantum materials in which electrons interact strongly and behave as quantum waves rather than particles. Furthermore, this material Very clean, which allows fluid-like behavior to be obtained directly."
In this material, the team etched a narrow channel flanked by a circular chamber, then ran an electric current through it and measured the electron flow. . In a standard material like gold, electrons always flow in the same general direction, even if they disperse to individual chambers and then return to the central channel. But in tungsten ditelluride, the electrons spin in a circular chamber, twisting direction and creating "vortices."
Levitov said: "Electron vortices can be expected in theory, but there has been no direct evidence. Seeing is believing. Now that we have seen it, it is a clear sign of being in this new system, in which electrons behave as a fluid, not individual particles."
Confirmation of a long-term prediction could help scientists design more efficient electronics, the team said.
The research was published in the journal Nature.
