Semiconductor Cavity Quantum Electrodynamics with Single Quantum Dots

Abstract

Semiconductor cavity quantum electrodynamics (cQED) with single quantum dots as artificial atoms and high quality factor cavies is a rapidly developing research field. Solid state platforms are a prerequisite for more wide spread exploitation of cQED effects, which hold promise for the realization of several key devices for quantum information processing and nano-optoelectronics, like single photon sources or ultra-low threshold lasers. Semiconductor systems are particularly attractive because they offer routes for electrical injection or electro-optical tuning. This talk will mainly focus on the presentation of cQED experiments in high-quality factor micropillar cavities containing semiconductor quantum dots (see Fig. 1). After a general introduction into semiconductor cQED with micropillar cavities, the recent progress made in our group on electrically driven micropillar cavities will be reported [1, 2]. By developing a process for planarizing and contacting quantum dot micropillars we fabricated devices with quality factors up to 16.000 for pillar diameters of 4 μm. Such devices feature pronounced cQED effects, like enhanced spontaneous emission, photon antibunching, high-β lasing and electro-optical tuning in both the weak or strong (see Fig. 2) coupling regime. Spatial determinism in cQED is of major importance for the exploitation of related effects on larger scale or for the realization of more complex device functionalities, e.g. the deterministic photonic coupling of remote quantum dots via spatially separated cavities and waveguides. Another main part of the talk will discuss our recent progress made in the field of device integration of site-controlled quantum dots into photonic crystal as well as micropillar cavities (see Fig. 3) [3, 4].