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Beyond Exponential Conductance Decay – Highly Conducting Molecular Wires Based on One- Dimensional Topological Insulators
Presented By: Liang Li
Abstract:
Over the past few decades, significant advancements in nanotechnology have enabled scientists to investigate and understand single-molecule electronics. These advances have allowed the integration of single molecules as different electronic components within macroscale circuits. Because of the small dimension of single molecules, electrons behave as waves when traveling through molecular junctions. Therefore, the conductance of a molecular junction is directly related to the electron transmission probability. In coherent and off-resonant transport, the conductance of an oligomeric molecular wire decays exponentially with increasing number of repeating units, which makes the conductance of a long oligomeric molecular wire inevitably lower than that of its shorter analogs. Scientists have been making great efforts to mitigate the exponential conductance decay, as long and highly conducting molecular wires are more desired for constructing molecule-based electronic circuits because they can decrease power loss and maintain signal integrity over long distances. An effective solution is to design molecular series to exhibit a reversed conductance decay, in which conductance increases exponentially with the number of repeating units. This dissertation aims to demonstrate that a special class of molecules, known as one-dimensional topological insulators (1D TIs), can exhibit anomalous conductance-length relationships, such as reversed conductance decay, due to their non-trivial edge states.
