Using a sliver of material shaped like a diving board or cantilever, researchers have detected a force that's a billionth the strength of a typical chemical bond. At 800 zeptonewtons, it's the most sensitive measurement of mechanical force ever.
This exquisite sensitivity may finally make it possible to mechanically detect a single electron's magnetism, say Dan Rugar and John Mamin of IBM Almaden Research Center in San Jose, Calif.
Electrons and most nuclei act like tiny bar magnets because of a quantum mechanical property called spin. Sensing an electron's spin would be a coup for Rugar and his coworkers. They've long been developing a type of magnetic resonance imaging (MRI) microscope for revealing identities and locations in solids of individual atoms–whose magnetism is much subtler than an electron's (SN: 6/11/94, p. 374). Since the early 1980s, scientists have used other types of microscopes to observe atoms by nonmagnetic means–but just on samples' su