A new approach to scanning tunneling microscopy (STM) has allowed Cornell and Boston University researchers to image individual atoms 100 to 1000 times faster than before. The STM uses quantum tunneling, or the ability of electrons to "tunnel" across a barrier, to detect changes in the distance between a needlelike probe and a conducting surface. Now, Cornell's Keith Schwab and colleagues have added a simple external radio source, which they can use in reflectometry measurements to obtain the distance between the probe and a sample surface much faster than is possible with a standard STM. The setup could be used to measure the precise temperature of particular atom on a surface and to detect movements 30,000 times smaller than a single atom.
The microscopic superhighway