Noise in atomic force microscopy

Abstract

In topographic images, the noise in the vertical position of the tip (i.e. the noise in the tip-sample distance) should be considerably smaller than the topography signal on the sample to be measured. If atomic steps are imaged, the noise should have an amplitude much smaller than 1 Å. In the following we do not consider noise due to floor vibrations or sound, but more fundamental limits of noise due to thermal excitation of the cantilever, or due to the detection limit of the preamplifier detecting the signal.