Researchers have successfully started a controlled movement within the core of an atom. They facilitated an interaction between the atomic nucleus and one of the electrons located in the atom’s outer shells. This particular electron could be manipulated and observed through the needle of a scanning tunneling microscope. The findings from this research present a possibility for storing quantum information within the nucleus, where it remains protected from outside interference.
Scientists at Delft University of Technology in the Netherlands have achieved a controlled movement in the core of an atom. They managed to make the atomic nucleus interact with one of the electrons found in the outermost shells of the atom. This electron can be controlled and detected using the needle of a scanning tunneling microscope. The results of this research, published today in Nature Communications, open up new possibilities for securely storing quantum information within the nucleus, safeguarding it from external disruptions.
For several weeks, the researchers focused their attention on a single titanium atom. “Specifically, a Ti-47 atom,” explains lead researcher Sander Otte. “It has one less neutron than the more common Ti-48, giving it slight magnetic properties.” This magnetism, referred to as ‘spin’ in quantum terms, acts like a compass needle that can align in various directions. The state of the spin at any moment represents a piece of quantum information.
Precisely tuned
The nucleus of an atom is situated in a relatively large empty space, far from the surrounding orbiting electrons, and is generally unaware of its surroundings. However, one exception exists: the very weak ‘hyperfine interaction’ allows the nuclear spin to be affected by the spin of a nearby electron. “It’s easier said than done,” remarks Lukas Veldman, who recently earned his PhD with honors for his work on this research. “The hyperfine interaction is so subtle that it only functions in a meticulously calibrated magnetic field.”
Voltage pulse
When all experimental conditions were optimal, the researchers applied a voltage pulse to disrupt the equilibrium of the electron spin, causing both spins to oscillate together for a brief moment. “Just as Schrödinger predicted,” states Veldman. In conjunction with these experiments, he performed calculations that surprisingly matched the observed fluctuations closely. The strong correlation between predictions and actual observations indicates that no quantum information is lost during the interaction between the electron and the nucleus.
Storing quantum information
The effective shielding against external factors makes the nuclear spin a promising candidate for storing quantum information. This ongoing research may bring that potential closer to reality. However, the primary motivation for the researchers goes beyond practical applications. Otte says, “This experiment grants humans the ability to influence matter at an incredibly tiny scale. To me, that insight alone makes the effort worthwhile.”
