Two radio signals reveal nuclear transitions in a single titanium atom
Researchers drove and detected nuclear transitions in one surface-supported titanium atom using separate radiofrequency channels. The peer-reviewed experiment kept the signal visible at magnetic fields where a simpler method fades. It offers a way to investigate an individual nuclear spin and its surroundings, while coherent quantum control and a working processor remain beyond the demonstrated result.
Science··Evening
A nucleus read through its electron
One titanium atom on an insulating magnesium oxide layer supplied the signal in a peer-reviewed nuclear magnetic resonance experiment. A scanning tunnelling microscope addressed the atom locally at about 0.4 kelvin. Titanium-47 carries a nuclear spin, a quantum property whose interaction with the electron spin splits the electron resonance into six lines. Atoms without nuclear spin provided a comparison. Changes in the heights of those lines revealed how the nucleus occupied its different states.[1]
Separate signals preserve the nuclear response
The apparatus used one radiofrequency channel in the gigahertz range to monitor electron resonance and another in the megahertz range to excite the nucleus. This separated driving from readout. Nuclear transitions remained visible between 200 and 1400 millitesla, including fields where the single-frequency response faded as electron and nuclear states mixed less strongly. The team distinguished four transition families and used their splitting to examine the nucleus’s local electric environment.[1]
Resonant excitation changes state populations
The populations of two nuclear levels became equal when the team applied a 49.3 megahertz signal at 450 millitesla. A 30.2 megahertz signal away from resonance left that population difference intact. Signal amplitudes are harder to compare because the cables and the microscope junction transmit each frequency differently. The measurements establish local nuclear driving and detection, while a coherence time and coherent nuclear operations remain unmeasured. Raw data and analysis code are available on Zenodo.[1]
