Friday 30/11/2007, 11am, room A5-01

Speaker: Dr. Alexia Auffèves - CNRS-Institut Neel - Grenoble.

Title: Cavity quantum electrodynamics in solid state devices: theoretical dreams and ongoing experiments Abstract

Solid state devices open a promising field for CQED experiments. When it is properly operated, a quantum dot behaves indeed as a two-level artificial atom. The quality factor of state of the art semi-conducting micro-cavities reach 106, while their modal volume approaches the ultimate volume λ3, allowing to observe the strong coupling regime [1-4]. Moreover, the radiation diagram of such cavities can be finely controlled [5], leading to the realization of efficient single photon sources and micro-lasers.

This talk aims at giving a glimpse of some of the research topics presently under study in the quantum optics group of Néel Institute (Grenoble, France). In particular, I will show that a single QD weakly coupled to a directional cavity provides a solid-state “ one-dimensional atom” [6]. This medium shows striking optical features, in particular, it is sensitive at the single photon level, which may have interesting applications in the field of optical computing. Experiments to probe this optical system are under progress.

Another recently opened field of research concerns the relaxation properties of a two-level atom in a very high finesse cavity. Thanks to major technological improvements, the Q factor of the best cavities is now of the same order of magnitude than the Q factor of the emitter they are coupled to, allowing to explore a new regime for CQED. In this regime, photons can be emitted at the cavity frequency, even if the atom and the cavity are strongly detuned. This puzzling behavior has already been observed in [4], and is qualitatively understood in [7]. Finally, I will discuss further possible refinements of the model.

References

[1] J.P. Reithmaier et al., Nature 432, 197 (2004). [2] T. Yoshie et al., Nature 432, 200 (2004). [3] E. Peter et al., Phys. Rev. Lett. 95, 067401 (2005). [4] K. Hennessy et al., Nature 445, 896 (2007). [5] S-H. Kim, S-K. Kim and Y-H. Lee, Phys. Rev. B 73, 235117 (2006). [6] A. Auffèves-Garnier, C. Simon, J. M. Gérard and J. P. Poizat, Phys. Rev. A 75, 053823 (2007). [7] A. Auffèves, B. Besga, J. M. Gérard and J.P. Poizat, arXiv:0710.2421.