Visualization of the electric current flowing through conducting structures via magnetic-force microscopy

Abstract

A technique for determining the spatially distributed current densities of micro-and nanosystems, which is based on measuring the magnetic fields of currents with the use of a magnetic-force microscope and subsequent calculations of the spatial current-density distribution from inversion of the Biot–Savart–Laplace equation, is presented. The technique is tested using specially prepared structures of different shapes with a current-conducting path width of about 1 µm, namely a ring and a meander. Two-dimensional current flow is demonstrated to have features associated with the shape of the tested structures. In particular, it is found that components and the current amplitude are changed at points where the structure shape undergoes variations.