How small is a molecule? The answer depends on the type of molecule. Researchers at the Michigan Technological University (Department of Physics) and the Advanced Nano Characterization Center (National Institute for Materials Science in Japan) have developed a new model to explain negative differential resistance (NDR). What does this mean in quantum physics? A strongly coupled single molecule-to-metal junction could act as an electronic switch. If successful, this model could revolutionize computers and other devices that rely on microscopic electronic processing. Care to read the abstract in the Physical Review Letters from the American Physical Society?