Interaction of Resonances and Antiresonances in Quantum Transport in the Presence of Weak Interelectron Repulsion

We study theoretically the interaction of resonances and antiresonances in the transmission spectrum of a two-level molecular conductor, taking into account weak interelectron Coulomb repulsion in the first order in perturbation theory (within the framework of the Keldysh diagram technique). It is known that in the absence of interaction, a Fano resonance, the formation of a bound state in the continuum, and the coalescence of resonances can be observed depending on the topology of the coupling of the system with the electrodes. These interference phenomena are important for applications in molecular electronics, sensing, and thermoelectricity. It is shown that all resonance features in the transmission spectrum demonstrate a shift towards the Fermi level in the electrodes if weak interelectron repulsion is taken into account. The general conclusions obtained for the two-level model are confirmed by calculations using the illustrative models of cyclobutadiene and benzene molecules.