Event Details

Some interesting optical manifestations in quantum confined excitonic systems

  • 2018-09-27
  • Dr. Bidisha Roy, Walter Schottky Institute of TU Munich, Germany

Optical and magneto-optical studies of excitons in a cylindrically stacked system of semiconductor quantum dots with type-II band alignment will be discussed in the first part, particularly addressing the intriguing observation of excitonic Aharonov- Bohm (AB) effect in these systems which gets revealed through magneto-photoluminescence (PL) emission. The AB signature indicated presence of built-in electric field in the system and a detailed spectral analysis of this otherwise purely quantum mechanical effect could lead to the determination of lateral excitonic size with up to sub-nanometer precision. In this light, I will also discuss the decoherence mechanisms in such quantum confined systems. In a second part, we will look at a plasmonic- semiconductor hybrid system of interest that enabled the tuning and manipulation of optical emission from an overlaid monolayer of two-dimensional transition metal di-Chalcogenide (2D TMDC) semiconductor material. Here I will discuss how the geometry-dependent plasmonic resonance of a nanoplasmonic array could induce a significant degree of linear polarization to the optical emission from an otherwise unpolarized atomically thin excitonic emitter at room temperature. The key factors governing such functional light-matter interactions in low dimensional semiconductor excitonic systems relevant to novel fundamental and applied interests will be the general intent of this talk.