Single Photon and Single Atom Sources for Quantum Information Processing

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

EIA-0218341 Mark Saffman University of Wisconsin-Madison Single-Photon and single atom sources for quantum informaiton processing This research project is demonstrating new ways of engineering single photon and single atom sources for a range of applications in quantum information science. The experimental approach starts with several thousand Rb atoms that are trapped at ultrahigh densities in a far-off-resonance optical beam. A many atom entangled state is then created using the dipole blockade mechanism that arises from atom-atom interactions in a dense atomic vapor as proposed recently by Lukin, et al. (2001). The trapped ensemble of entangled atoms is manipulated optically to create novel sources at the level of single atoms and single photons. Using additional near-resonant laser beams atoms are selectively ejected from the trap depending on their internal state. This enables deterministic loading of a single atom in an optical trap, as well as "single-" or "multiple-atom-on-demand" sources with optically controllable trajectories. By using entanglement between atoms in ground and excited internal states a single-photon source is being created that has a diffraction limited, steerable emission pattern. This approach is enabling a number of novel solutions to manipulation of matter and fields at the level of single quantum objects with applications to quantum communication, cryptography, and computing. A key component of this work is the enhancement of its impact through outreach and educational activities. Presentations at local schools and lectures for the general public on quantum information and computation are allowing the University of Wisconsin to communicate to the local community, including the burgeoning photonics industry in the Madison area, the importance and intellectual excitement of this research program.