When Conductance Is Less than the Sum of Its Parts: Exploring Interference in Multiconnected Molecules

We investigate, the electron transmission through molecules with multiple connections to the leads and compare this with the transmission through the same molecules where only select connections have been made. This enables us to probe the transmission through the individual pathways through the molecules and investigate their interaction. Generally, we see that the transmission of the multiconnected molecules differs from those obtained from a sum of their parts because of coherence effects between the paths through the molecules. The only exception to this trend is a case where the molecule can be considered as two separate parts, isolated electronically from each other via meta connections. We also explore the local currents though these molecules and separate these into channels, which reveals how this coherence comes into play.