Solid State and Optics Seminar

Wednesday, April 5, 2006

1:00 p.m.

107 Mason Lab

"Semiconductor Quantum Dots for Quantum Optics and Quantum Information"

Dr. Richard Mirin,
N.I.S.T.

Abstract

Epitaxial InGaAs/GaAs quantum dots are of interest for a variety of applications in quantum information and quantum optics. These quantum dots are true realizations of a three-dimensional “particle-in-a-box,” and one important consequence of this three-dimensional quantum confinement is the atomic-like density of electronic states. I will describe our experiments on using individual quantum dots as single photon on-demand sources. I will also describe how we integrate these quantum dots into monolithic microcavities to help enhance both the spontaneous emission rate and the capture efficiency of the emitted single photons. These microcavities also enable us to investigate indistinguishable photons, which are interesting for making engineered quantum states of light and for linear optical quantum computing. In addition to single photon sources, my group has recently used high-resolution spectral hole burning to measure the coherence time of the quantum dot optical transition. We have measured a coherence time of 1.76 ± 0.21 ns, which approaches the spontaneous emission lifetime limit and is about a factor of 2 longer than other reports of coherence times in epitaxial quantum dots. We attribute these differences to differences in epitaxial layer design as well as improved measurement techniques.

Host: Jack Harris