Nano-scale studies of quantum phenomena by scanning probe spectroscopy

Abstract

Phenomena on the nanometer scale are dominated by quantum effects. They can be visualized in a fascinating way either by the scanning tunneling microscope (STM), which itself is based on a quantum-mechanical effect, electron tunneling, or by related scanning probe methods. These so-called near-field microscopies allow the direct observation of the wave nature of electrons in solids and the determination of their effective mass as well as their spin state. Atomic resolution is obtained by STM on an energy scale which is a million times smaller than that of X-rays. Therefore, quantum effects in solids, which usually occur on energy scales of several millielectronvolts, become accessible while operating at high spatial resolution down to the atomic level. The detailed understanding of quantum phenomena at the nanometer scale will constitute the foundations of the nanotechnology age, which will be dominated by the digital control of matter at the level of single atoms and molecules, single electrons, as well as single spins.