Mach-Zehnder quantum interference rules in hydrocarbons with substituents

摘要

We have investigated the conditions of quantum interferences in hydrocarbons with substituents using density functional theory and tight binding approximation combined with non-equilibrium Green’s function technique. The chosen model systems, namely benzene and tripyridyl–triazine molecules, have elucidated three prominent rules. The ‘first rule’ is the occurrence of inevitable, destructive quantum interference when 1,3-benzene ring incorporates single substituent at the fifth site. The ‘second rule’ is the chaotic occurrence of quantum interferences due the position and/or type of the substituents. The ‘third rule’: the substituents decrease (increase) the probability of destructive (constructive) interferences.