Quantum-QuBIC: Deterministic Cavity Quantum Electrodynamics for Quantum Information Studies

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

EIA- 0130414 Dan M. Stamper-Kurn University of California-Berkeley Title: Deterministic Cavity quantum Electrodynamics for Quantum Information Studies In the young field of quantum information science, theoretical investigations have quickly identified potentialities which are so astounding in scope (exponential speed-up of computation, the insecurity of current cryptographic schemes) that a focused experimental activity must be undertaken. This project is pursuing a fundamental experimental advance in one potential arena for the implementation of these theoretical ideas is proposed: the synthesis of optical and atomic quantum information resources through cavity quantum electrodynamics (CQED). While theoretical developments indicate that CQED devices offer a scalable and powerful architecture for quantum information processing, a key missing element which stands in the way of further progress is the deterministic loading of the atom-cavity system. To mend this gap, a powerful yet straightforward integration of the experimental techniques of laser cooling, magnetic trapping and Bose-Einstein condensation with cavity quantum electrodynamics is underway. This synthesis is clearly beneficial to quantum information processing, combining well controlled, stationary qubits comprised of trapped atoms wherein quantum information is stored in long-lived internal states, "flying qubits" in the form of photons emitted from the cavity, and a means of strongly coupling the two. This ambitious effort will enable a broad range of breakthroughs and innovations in the field of quantum information science. For this project, an evaporatively-cooled, and at times quantum degenerate, atomic gas is produced outside the confines of a high-finesse optical cavity, and then adiabatically placed inside the cavity to provide a reservoir of ultracold atoms. Single atoms, or a countable number of atoms, are "activated" from this "passive" reservoir by a transition between atomic hyperfine states, and are then used for a wide range of basic applications with direct relevance to quantum information and communication schemes. These applications include the generation of single photons on demand, the generation of non-classical number states of the optical field, the implementation of Raman CQED by which the atom-cavity system can be programmatically switched on and off, and an exploration of quantum and non-linear optical properties of quantum degenerate gases at the single photon level.