Investigation of fundamental physical properties of coupled quantum well - quantum dot systems emitting in the near infrared range of 1.3 - 1.55 micrometer. (QuCoS - Quantum Coupled Systems)

The subject of this research is to investigate the basic physical properties of coupled two-dimensional (quantum well) and zero-dimensional (quantum dots) semiconductor-based quantum subsystems characterized by the ground state photon emission wavelength in the near-infrared (1.3 – 1.55 µm) spectral range.

The major aim of the project is to perform the theoretical and experimental studies of several closely related issues.

The hypothesis we intend to verify is that by a careful selection of physical interactions and semiconductor material properties one can design and produce a quantum system with widely and precisely controllable efficiency of charge/exciton/spin transfer from a QW to the QD ground state, both separated in the real space, while keeping three conditions: (i) the QD ground state is the lowest energy state for an entire coupled system, (ii) it keeps its localized character (atomic-like character), and (iii) emits photons in the near-infrared spectral range of 1.3 – 1.55 µm.

As a long-term objective, we anticipate that the results of our investigation will point out the most critical issues related to a design of the coupled QW-QD systems of desired parameters. We intend to verify the role of a quantum mechanical coupling between spatially separated subsystems of different dimensionality and demonstrate how to control it on the basic physical level. This knowledge will possibly be used in the development of novel optoelectronic and spintronic devices of superior parameters (i.e. fast modulated lasers, switches, long storage time and fast read/write memories etc.), which rely on the QW-coupled-QD system architecture.

Joint project with Wroclaw University of Technology, Israel Institute of Technology, Technion, Haifa and with Institute for Theoretical Physics, University of Bremen.