Fabrication of quantum devices by Angstrom-level manipulation of nanoparticles with an atomic force microscope

We describe a technique for the fabrication of lateral nanometer-scale devices, in which individual metallic nanoparticles are imaged, selected and manipulated into a gap between two electrical leads with the tip of an atomic force microscope. In situ, real-time monitoring of the device characteristics is used to control the positions of the particles down to atomic accuracy and to tune the electrical propel-ties of the device during fabrication. Using this technique we demonstrate a nanomechanical switch as well as atomic-scale contacts that an stable at quantized conductance levels on the timescale of hours at room temperature. (C) 1998 American Institute of Physics.