Credit: Image courtesy of Megan Holtz, Dennis Meier, and Emily Falco
Working towards rewritable nanoscale wires, researchers controlled electrical conductivity in 2-D ferroelectric domain walls by applying a voltage (V). The domain walls behaved like an electric switch. The charges responsible for this behavior were localized to within a few atom widths (a nanometer) of the domain walls, the barriers between regions with different electronic properties, in erbium manganite. In the atomic-resolution electron microscopy image, the positive (red) and negative (blue) polarizations come together in the white region. This polarity mismatch forms a positively charged (head-to-head) domain wall. Applying a voltage added more charge carriers to the domain wall, switching the conductivity of the channel.