Researchers from Delft University of Technology in The Netherlands have been in a position to initiate a controlled movement within the very heart of an atom. They caused the atomic nucleus to interact with one in every of the electrons within the outermost shells of the atom. This electron may very well be manipulated and browse out through the needle of a scanning tunneling microscope. The research, published in Nature Communications today, offers prospects for storing quantum information contained in the nucleus, where it’s protected from external disturbances.
For weeks on end, the researchers studied a single titanium atom. “A Ti-47 atom, to be precise,” says research leader Sander Otte. “It has one neutron lower than the naturally abundant Ti-48, which makes the nucleus barely magnetic.” This magnetism, the ‘spin’ in quantum language, might be seen as a kind of compass needle that may point in various directions. The orientation of the spin at a given time constitutes a bit of quantum information.
Precisely tuned
The nucleus of an atom floats inside a — comparatively — giant void far-off from the orbiting electrons, oblivious of its environment. But there’s one exception: as a result of the extremely weak ‘hyperfine interaction’, the nuclear spin might be influenced by the spin of one in every of the electrons. “Easier said than done,” says Lukas Veldman, who recently defended his PhD dissertation on the research with honours. “The hyperfine interaction is so weak that it’s effective only in a really small, precisely tuned magnetic field.”
Voltage pulse
Once all experimental conditions were met, the researchers used a voltage pulse to push the electron spin out of equilibrium, after which each spins wobbled together for a fraction of a microsecond. “Exactly how Schrödinger predicted,” says Veldman. Alongside the experiments he performed calculations that reproduced the observed fluctuations surprisingly well. The strong agreement between observations and predictions demonstrates that no quantum information is lost throughout the interaction between electron and nucleus.
Storing quantum information
The efficient shielding from the environment makes the nuclear spin a viable candidate for holding quantum information. The present research may bring that application one step closer. But that will not be what primarily drives the researchers. Otte: “This experiment gives humans influence on the state of matter on an unimaginably small scale. To me, that alone makes it definitely worth the effort.”
