Tunneling

Physics Quantum Mechanical effect of transitioning through a classically forbidden energy state.

Applications One of the most popular applications is in electron-tunneling microscopes (see scanning tunneling microscope) that are used to see objects that are too small to see using conventional microscopes. Electron tunneling microscopes overcome the limiting effects conventional microscopes (optical aberrations, wavelength limitations) by scanning the surface of an object with tunneling electrons.

See also Quantum Mechanics.