Under the appropriate case, electrons can actually "freeze" into a strange solid form.Now, physicists in Berkeley laboratory created and took the first direct images of this structure.Theoretical physicist Eugene Wigner first predicted the existence of this crystal in the 1930s.It was not until a few years ago that scientists directly detected and used their imaging for the first time.
Electronics taken at the bottom right to form Vogners scan tunnel microscopy image
NowFor the first time, a research team made a new electronic quantum phase-a related structure called Vigner molecular crystals-imaging.Fundamentally, this is the same solid electron phase. The difference is that the electronic community instead of a single electron settle in each position of the lattice.
Electronics usually flow more or less in the materials, a bit like an disorderly liquid.However, if they can slow down their exercise speed, another characteristic will be replaced, that is, their electrostatic exclusion force.Because electrons have the same charge, they will naturally exclude each other. Therefore, when they stop exercise, they will push a certain distance from each other and lock it there.This forms a Vigner crystal phase.
In order to manufacture Vigner molecular crystals, researchers need a new framework to fix electrons to form "molecules".They started from the 49 -nanometer thick hexagonal boron nitride layer, and then stacked two layers of tungsten sulfide, with only one atomic thickness each.One of the layers of twisted from the second layer to 58 degrees.
Then, the electrons are incorporated into the "TWS2 Moore Super Crystal". Sure enough, two or three electrons are gathered in each cell of the lattice.These small groups are essentially electronics, and they together constitute an elusive Vogner molecule crystal.
Facts have proved that truly observing crystals is another challenge.Scanning tunnel microscope (STM) is usually used to shoot images of this scale, but the electric field generated by the needle tip often destroys the vulnerable configuration of electrons in the crystal.The research team found a method to minimize the electric field so that they could capture the first image of this phenomenon.
Researchers plan to further study Vigner molecular crystals in future experiments to see what kind of applications they will have.
This research is published in the "Science" magazine.
