Strong-Coupling of Quantum Dots and Micro-cavities for Efficient Single and Double Photon Sources and Quantum Logic

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

0323141 Raymer The PI will implement a novel approach for reaching the cavity-QED strong-coupling regime with a single semiconductor quantum dot (QD) and a mode of an optical micro-cavity. Such coupling, not yet achieved in any laboratory, implies that a single photon can strongly drive the QD, and that emission from an excited-state QD will occur deterministically and predominantly into a single mode of the light field. This extreme degree of control at the single-quantum level will potentially enable the PI to develop several useful applications in Quantum Information Processing: 1. Deterministic production of single photons on demand (useful for ensuring the security of quantum cryptography); 2. Writing and reading of quantum information into and out of material systems; 3. Deterministic production of pairs of polarization-entangled photons on demand (useful as a resource for quantum communication or for linear-optics computing); 4. Quantum information processing or computing. The immediate goal will be to demonstrate that the external-cavity system already constructed in our laboratory will provide a sufficient level of coherent coupling between a QD and an optical cavity mode to meet requirements for QD-based Quantum Information Processing (QIP). The second goal during the 3-year funded period will be items 1 and 2 above. The research will contribute to a potential revolution in communications technology if quantum techniques truly become operable. The research here will contribute to the development of efficient solid-state sources of single photons and photon pairs, as well as the coherent control of single quantum dots that is needed for manipulating electronic and spin states in these systems for quantum computing. Quantum Information Science is popular with students - both graduate and undergraduate. It is attracting students into research. Undergraduates, including male and female, have worked on the project. The project has also attracted visiting scientists and students from abroad, providing a culturally broadening experience for the students. The material is finding its way into undergraduate and graduate-level courses. The PI recently initiated and taught a new course at the level of undergraduate non-science majors, called The Physics Behind the Internet, for which he has recently authored a textbook.