Efficient excitonic population transfer in a coupled quantum dot – metal nanoparticle structure interacting with a chirped laser pulse

A relatively new area of ​​active research combining nanophotonics, quantum optics and quantum technology is studying the optical properties of complex structures containing plasmonic nanostructures and quantum systems, such as molecules and semiconductor quantum dots. Coherently controlled quantum systems coupled to plasmonic nanostructures are considered active nanophotonic structures and are expected to have important applications in many fields, such as nanotechnology and quantum computing. An important problem studied in these systems is the effect of plasmonic nanostructure on controlled population transfer in the exciton state of the quantum dot, starting from the ground state of the quantum dot. The studies to date on the controlled population dynamics of quantum dots coupled to plasmonic nanostructures have dealt mainly with the preparation of the exciton state by resonant methods, while more recently there has been work on optimal pulses as well. The resonant methods give excitonic population with very high efficiency, but only for a specific combination of pulse width and electric field value. Also, the performance of the resonance methods is quite sensitive to variations in the parameters of the laser fields used. Alternatively, there are very important methods of population transfer and quantum control that are adiabatic that are not sensitive to changes in the parameters of the laser fields. One of these methods is rapid adiabatic passage. This method has been used extensively in isolated quantum dots, both theoretically and experimentally. In the present work, we apply the method of rapid adiabatic passage to a quantum dot coupled to a plasmonic nanostructure, specifically a metal nanoparticle, and examine the excitonic state preparation efficiency for different distances between the quantum dot and the metal nanoparticle. In particular, results for the interaction of the coupled quantum dot – metal nanoparticle structure with linearly chirped Gaussian laser pulses are presented.