Self-Assembled InAs/InP Quantum Dots Transform into Quantum Rings without Capping

Transformation of self-assembled InAs/InP quantum dots into quantum rings without capping.

Transformation of self-assembled InAs quantum dots (QDs) on InP(100) into quantum rings (QRs) is studied. In contrast to the typical approach to III--V semiconductor QR growth, the QDs are not capped to form rings. Atomic force micrographs reveal a drastic change from InAs QDs into rings after a growth interruption in tertiarybutylphosphine ambient. Strain energy relief in the InAs QD is discus...

Nanophotonic Waveguides by Self-Assembled Quantum Dots

In order to construct ultra-high density photonic integrated circuits, innovative techniques are required to circumvent the fundamental restriction set by Heisenberg’s Uncertainty Principle and the resulting diffraction limit. Traditionally, waveguides adhere to a lower bound in size roughly equal to the propagating wavelength to allow for energy confinement and minimal crosstalk. However, prog...

Self-assembled Nanorings and Stressor Quantum Dots

Kondo excitons in self-assembled quantum dots

A. O. Govorov, K. Karrai, and R. J. Warburton Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA Institute of Semiconductor Physics, 630090 Novosibirsk, Russia Center for NanoScience and Sektion Physik, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, 80539 München, Germany Department of Physics, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom ~R...

Charged Excitons in Self-assembled Quantum Dots

We have succeeded in generating highly charged excitons in InAs self-assembled quantum dots by embedding the dots in a field-effect heterostructure. We discover an excitonic Coulomb blockage: over large regions of gate voltage, the exciton charge remains constant. We present here a summary of the emission properties of the charged excitons. INTRODUCTION An exciton is the elementary excitation i...