Researchers at the National Institute of Standards and Technology (NIST) created grids of tiny clumps of atoms known as quantum dots and studied what happens when electrons dive into these archipelagos of atomic islands. Measuring the behavior of electrons in these relatively simple setups promises deep insight into how electrons behave in complex real-world materials and could help researchers develop devices that make powerful quantum computers and other innovative technologies possible.
In work published in nature communication, the researchers made several 3-by-3 lattices of precisely cut quantum dots, each made up of one to three phosphorus atoms. Attached to the grid were electrical leads and other components that enabled electrons to flow through them. Lattices provided playgrounds in which electrons could behave in near-ideal, textbook-like conditions, free from the confounding effects of real-world materials.
The researchers injected electrons into the grid and observed how they behaved as the researchers varied conditions such as the distance between the points. For lattices in which the dots were close, the electrons tended to spread out and act like waves, essentially in different places at the same time. When the dots were far apart, they were sometimes trapped into single dots, like electrons in materials with insulating properties.
Advanced versions of the grid would allow researchers 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 accurately simulate. It would open the door to full-fledged “analog quantum simulators” that could unlock the secrets of exotic materials such as high-temperature superconductors. It could also provide clues on how to create materials, such as topological insulators, by controlling the geometry of the quantum dot array.
In related work just published in ACS Nano, the same NIST researchers have improved their fabrication method so that they can now reliably create a set of identical dots with exactly one atom each, leading to an even more ideal environment needed for a fully accurate quantum simulator. The researchers set their sights on making such a simulator with a larger grid of quantum dots: A 5×5 array of dots can produce a rich electron behavior that is impossible to simulate even the most advanced supercomputers.
Material is provided by National Institute of Standards and Technology (NIST). Note: Content may be edited for style and length.