My current research is related to theoretical problems of molecular electronics, nano-photonics and plasmonics.
We developed theory for light-induced current by strong optical pulses in molecular tunneling junctions. We proposed an optical control method using chirped pulses for enhancing charge transfer in unbiased junctions where the bridging molecule is characterized by a strong charge-transfer transition. The effects of local field for realistic junction geometries and non-Markovian response of the molecule were also taken into account.
We considered exciton effects on current in molecular nanojunctions. Our calculations have shown that in case of noninteracting electrons this interaction leads to reduction in the current at high voltage for a homodimer bridge. In other words, we predicted the effect of “exciton” blocking. We also studied the influence of both exciton effects and Coulomb repulsion on current in molecular nanojunctions. We show that dipolar energy-transfer interactions between the sites in the wire can compensate Coulomb blocking for particular relationships between their values. Tuning this relationship may be achieved by using the effect of plasmonic nanostructure on dipolar energy-transfer interactions.
We have developed a pseudoparticle nonequilibrium Green function formalism to study the coupling between plasmons and excitons in nonequilibrium molecular junctions. The formalism treats plasmon-exciton couplings and intramolecular interactions exactly and is shown to be especially convenient for exploration of plasmonic absorption spectrum of plexitonic systems. This study opens a way to deal with strongly interacting plasmon-exciton systems in nonequilibrium molecular devices.
We have proposed new approaches to coherent control of transport via molecular junctions. The methods are based on the application of intrinsic semiconductor contacts and optical frequencies below the semiconductor bandgap, and using graphene electrodes as a platform for effective photon assisted tunneling through molecular conduction nanojunctions.
We have also developed a theory of nonlinear non-steady-state organic “plasmonics” with strong laser pulses.