Researchers at IBM’s Almaden Research Center in San Jose, California, have detected the first faint magnetic signal from a single unpaired electron, paving the way for future efforts to produce three-dimensional images of molecules.
To make out the barely perceptible force, nanotechnologist Daniel Rugar and his team built a silicon cantilever one-thousandth the width of a human hair, attached a magnetic particle at the tip, and placed it near a so-called unpaired electron. By manipulating magnetic and electromagnetic fields, they flipped the electron’s orientation, changing the vibration frequency of the cantilever. Traditional magnetic resonance imaging works in a similar way, tracking the magnetic response of protons to assemble a 3-D image. However, Rugar says, “the magnetism from protons is very, very weak—you would need a million trillion protons in your sample just to pick up enough magnetic energy to make one pixel in the image.”
Pinpointing an electron via magnetic ...
