Speaker : Dr. Bidisha Roy, Alexander von Humboldt Postdoctoral Research Fellow, Walter Schottky Institute, TU Munich, Germany.
Venue : CeNSE Auditorium
Date & Time : 25th September, 2018, 4-5:30 PM
Abstract:
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 the second part, I will speak about a plasmonic- semiconductor hybrid system 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 emitter at room temperature.
The keys for such functional light-matter interactions in low dimensional systems relevant to novel fundamental and applied interests will be the focus of this talk.
Biography:
- Alexander von Humboldt Postdoctoral Research Fellow (2015- 2017): Walter Schottky Insititute, Technical University of Munich, Germany
- Postdoctoral Research Fellow (October 2013- July 2014): Queens College of The City University of New York, USA.
- Ph.D in Physics (2007- 2013), Graduate School and University Center of The City University of New York, USA.
- M.Sc. in Physics (2005- 2007): Indian Institute of Technology- Bombay, India.
- B.Sc. - Physics Honours (2002- 2005): Presidency College, University of Calcutta, India.