Fast quantum logic gates using optically trapped neutral atom arrays

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

The application of controlled quantum dynamics to computational problems has been one of the most important developments in information science in the last two decades. This project studies the use of optically trapped arrays of neutral Rb atoms for creating a multi-qubit quantum information processor. Focused laser beams will be used to manipulate the quantum states of the atoms. Single qubit rotations between internal ground states will be performed by optically stimulated Raman transitions. Two-qubit conditional logic operations will be performed by coupling the atoms to highly excited Rydberg states. The Rydberg states of neutral atoms have strong dipole-dipole interactions which provide a mechanism for fast conditional logic gates with high fidelity. It is projected that single and two-qubit gates will be possible at speeds greater than 1 MHz. The use of Rydberg interactions for deterministic loading of single atoms which will result in a scalable multi-qubit device will also be studied experimentally. As part of this work new knowledge will be gained on the dynamics of strongly interacting Rydberg atoms. The project includes new technical developments in high speed Rydberg state excitation and low-decoherence optical traps which will advance the state of the art for optical manipulation of the external and internal states of cold atoms. The broader impacts of this work are twofold. First, this research is an important step towards realizing the dream of a large scale quantum processor that exceeds the capabilities of conventional classical computers. The availability of such a device will have far reaching impact on numerical mathematics, information security, and problems in the simulation of quantum systems related to the development of new, technologically valuable materials. Second, the research program will contribute to the training of students and postdoctoral researchers for careers in science and engineering. People from diverse backgrounds will be educated and trained in modern experimental science, as well as in abstract concepts that bridge the boundary between physics and information science. Training will occur via curriculum enrichments, and through direct participation in our University based research program. We will also inform the local community about the importance of physics to information technology, and the new developments in the area of quantum information science. Outreach to the public will be facilitated by public visiting days at the Physics department, laboratory tours, and faculty visits to local schools.