Delft physicists flip a single atom's nuclear spin using radio waves

[Christopher_15]

Physicists in the Netherlands have found a surprising way to control the nucleus of a single atom. Interesting Engineering reports that researchers at Delft University of Technology used a modified scanning tunnelling microscope to flip an atom's nuclear spin with radio frequency signals

The work was led by Hester Vennema, who refined a technique called double magnetic resonance. Two signals are applied at once, one targeting the electron spin and one targeting the nuclear spin, so the team can adjust and study them separately. Nuclear spin transitions usually happen at frequencies 100 to 1,000 times lower than electron spin transitions

The surprise was that the nuclear spin flipped even when it was largely disentangled from the electron spin. Earlier Delft work had relied on the coupling between the two to steer the nucleus. Group leader Sander Otte said that, according to their simple understanding, this should not happen, and that the nuclear spin should not be sensitive to the electrical signals from the microscope at all

Nuclear spins are very well isolated from noise, which makes them attractive candidates for storing quantum information for long periods. The research is published in Nature Communications

The mechanism behind the effect is still unexplained, which is part of what makes it exciting. This is not yet a working quantum memory, and reliable control and readout in real devices still need to be shown. Unexpected results like this often lead to new techniques, though

Could single atom nuclear spins become practical quantum memories? And how often do surprises like this lead to breakthroughs?

Scientists flip single atom's nuclear spin using radio wavesinterestingengineering.com

[Lampard]

Scanning tunnelling microscopes are amazing tools. Manipulating single atoms on a surface still feels like science fiction. Delft has been a leader here for years. Their atomic scale work is world class. Few labs can do this