Coherent Control of Quantum Dots

Quantum dots (QDs) are semiconductor nanocrystals that confine electrons and holes on a nanometer size scale. At these sizes the electron is confined to within its De-Broglie wavelength, and therefore occupies discrete energy levels that are analogous to those of a single atom. For this reason QDs are oftern referred to as "artificial atoms". QDs are most commonly fabricated using epitaxial techniques, such as Molecular Beam Epitaxy (MBE), or by colloidal chemistry. The images below show an atomic force microscope image of epitaxially grown indium arsenide quantum dots (left), as well as an SEM image of colloidally grown QDs deposited on a glass slide.

Our groups studies methods to strongly interact quantum dots with light by placing them in photonic crystal cavities. These cavities create strong aton light interactions that can be used to directly manipulate quantum dot states and interface them with single photons for quantum information processing. We are also studying ways to manipulae the spin of QDs to achieve long lived quantum coherence.

Relevant publications:

Hyochul Kim, Deepak Sridharan, Thomas Shen, Glenn Solomon, and Edo Waks, "Strong coupling between two quantum dots and a photonic crystal cavity using magnetic field tuning," Opt. Exp. 19, 2589-2598(2011)

Edo Waks and Jelena Vuckovic, "Dipole Induced Transparency in Drop-Filter Cavity-Waveguide Systems," Phys. Rev. Lett. 96, 153601 (2006).