Modifying conventional differential conductance techniques improves speed and accuracy while reducing noise.

The demand for smaller, lower power electronic devices is fueling nanotechnology development. Researchers are striving to understand the quantum level structure and behavior of nanoscale devices and how these affect electrical properties. This makes it possible, for example, to observe or predict when tunneling occurs, calculate a device’s density of states, understand conduction phenomena in cryogenic environments, and create artificial atoms in which energy quantization can be modified based on material structure and geometry.

In the macroscopic world, conductors may have obeyed Ohm’s Law. In the realm of nanotechnology, Ohm’s definition of resistance is often irrelevant. The slope of the I-V (current-voltage) curve for a nanoscale device may not be a fundamental constant of the material. Therefore, measurements of an I-V curve’s slope at a large number of points are needed to study nanodevices. This plot of differential conductance (dG = dI/dV) is one of the most important measurements made on nanoscale devices, but it presents a unique set of challenges. Fortunately, new measurement techniques are making this type of study much easier.

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