Scientists from the University of Wollongong (UOW), working with colleagues from China’s University of Beang, Nankai University and the Institute of Physics of the Chinese Academy of Sciences, have successfully created an atomic scale, a two-dimensional electron grid with potential applications in electronics and quantum computing.
Research Paper published in November issue Scientific achievements,
Kagomevaya lattice is named after the traditional Japanese model of bamboo, consisting of alternating triangles and hexagons.
The research team created a kagome lattice by layering and twisting the two nanolayers of silicene. Silicon is a silicon-organic, monoatomic, Dirac fermionic material with a hexagonal honeycomb structure whose electrons can be accelerated near the speed of light.
However, when silicene is curled into a kagoma lattice, the electrons become "trapped", spinning in the hexagons of the lattice.
Dr. Yi Du, who heads the Scanning Tunneling Microscopy (STM) team at the Institute of Superconducting and Electronic Materials (ISEM) UOW and the Beihang-UOW Joint Research Center, is the author of the relevant document.
He said that scientists have long been interested in creating a two-dimensional Cagomet lattice because of the useful theoretical electronic properties that such a structure would have.
“Theorists predicted a long time ago that if you turn into an electronic grid of Kagoma, destructive interference means that electrons, instead of flowing, will instead turn into a whirlwind and close in a grid. This is equivalent to someone who loses their way into the maze and never went out, ”said Dr. Du.
“It is interesting that electrons will be free only when the lattice collapses, when you create a rib. When an edge is formed, the electrons will move with it without any electrical resistance — it has a very low resistance, so very low energy and electrons can move very quickly, at the speed of light. This is of great importance for the design and development of low-cost devices.
“Meanwhile, with a strong so-called spin-orbit coupling effect, new quantum phenomena, such as the friction quantum Hall effect, are expected to appear at room temperature, which will contribute to the creation of quantum devices in the future.”
While the theoretical properties of the electronic grating of the kagome made it of great interest to scientists, the creation of such a material turned out to be extremely difficult.
“In order for it to work as predicted, you have to make sure that the lattice is constant and that the lattice lengths are comparable to the electron wavelength that controls a variety of materials,” said Dr. Du.
“This should be the type of material on which an electron can move only along the surface. And you need to find something that is conductive, and also has a very strong spin-orbit coupling effect.
"There are not so many elements in the world that possess these properties."
The one element that makes is silicen. Dr. Dyu and his colleagues created their two-dimensional electron lattice from Kagoma, twisting two layers of silicon. At a turning angle of 21.8 degrees, they formed a Kagomet lattice.
And when the researchers put electrons into it, he behaved as predicted.
“We observed all the quantum phenomena predicted theoretically in our artificial Cagomet lattice in Silicon,” said Dr. Du.
The expected benefits of this breakthrough will be much more energy efficient electronic devices and faster, more powerful computers.
Kagome Metal: Physicists have discovered a new quantum electronic material
Zhi Li et al. Realization of a flat strip with a possible non-trivial topology in the Kagome electron lattice, Scientific achievements (2018). DOI: 10.1126 / sciadv.aau4511