NIST's grid of quantum islands could reveal secrets for powerful technologies
Researchers created a grid of quantum dots (center) ranging from one to three phosphorus atoms deposited onto a plane embedded in silicon and studied the properties of electrons injected into the grid. Credit: Wang et al/NIST

Researchers at theNIST have created grids of tiny clumps of atoms known as quantum dots and studied what happens when electrons dive into these archipelagos of atomic islands Deep insights into how electrons behave in complex real-world materials can be gained by measuring their behavior in these relatively simple setups.

In work published in Nature Communications, the researchers made multiple 3-by- 3 grids of quantum dots, each consisting of one to three phosphorus atoms. The grids had electrical leads attached to them. The grids made it possible for electrons to behave in a way that was textbook-like and free of the effects of real world materials.

As the researchers varied the spacing between the dots, they injected electrons into the grids to observe how they behaved. The electrons spread out and acted like waves for grids in which the dots were close. The dots would get trapped in individual dots when they were far apart.

Researchers would be able to study the behavior of electrons in controllable environments with a level of detail that would be impossible for the world's most powerful conventional computers to reproduce. It would open the door to "analog quantum simulators", which would allow us to understand the secrets of exotic materials such as high- temperature superconductors. The geometry of the quantum dot array could be controlled by it.

The NIST researchers improved their fabrication method so that they can now reliably create an array of identical, equally spacing dots with exactly one atom each, leading to even more ideal environments needed for a fully accurate quantum simulation. A 5x5 array of quantum dots can produce rich electron behavior that is impossible to reproduce in the most advanced computers.

Experimental realization of an extended Fermi-Hubbard model using a 2D lattice of dopant-based quantum dots was reported. There is a DOI titled " 10.1038/s41467-022-34 220-w".

Jonathan Wyrick is the author of Enhanced Atomic Precision Fabrication by Adsorption of Phosphine into engineered Dangling Bonds on H–SI. The book is titled "acsnano.2c08162."

Journal information: ACS Nano , Nature Communications