1 August 27, 2012 Tailoring Light-Matter Interaction in Nanophotonic Environments Petru Tighineanu Quantum Photonics group

-In quantum optics we often desire STRONG light-matter interaction. 2 -The implementation of quantum optics in nanophotonics. Energy

We will address two basic questions: 1.How strongly are QDs capable of coupling to the light field? 2.To which extent do QDs behave as point-like sources? 3

4 Coulomb confinement Dimensional confinement

5 Coulomb confinement Dimensional confinement

6 Spherical QD within the dipole approximation Experimental evidence?

7 Energy WL h e QDGaAs Free space Structured environment

8 Measured decay rate The rates are separated

9 Fast decay rate but small OS and low QE. Reason? Strain effects, inhomogeneous material composition.  Future challenge. Stobbe et al, PRB 82, (2010).

We will address two basic questions: 1.How strongly are QDs capable of coupling to the light field? 2.To which extent do QDs behave as point-like sources? 10

11 n=1 0 =400 nm a=0.5 nm  ka = << 1 n=3.5 0 =900 nm a=20 nm  ka = 0.5 ≈ 1

12 Andersen, Stobbe, Sørensen, and Lodahl, Nat. Phys. 7, 215 (2011).

13 Andersen, Stobbe, Sørensen, and Lodahl, Nat. Phys. 7, 215 (2011).

14 Dipole approximation: Beyond DA:  Light and matter degrees of freedom are no longer independent.  Decay dynamics are no longer determined by LDOS.

15 Theoretical computation within the envelope function approximation fails to reproduce experimental results. In QDs translational symmetry is broken => EFA becomes questionable.  Future challenge to develop a self-consistent microscopic model.

16 1.Large QDs have the potential of exhibiting huge coupling strength to light. 2.QDs are mesoscopic entities, NOT point dipoles.