LKB - Cavity Quantum Electrodynamics


Introductory posters presenting basic theoretical framework, experimental techniques, and most spectacular experimental results of the group obtained during the last several years.


♦ Le Prix Nobel de Physique 2012
Poster (in french) presented on the Festival of Science (la Fête de la Science) at the University of Pierre and Marie Curie.

♦ Electrodynamics of simple systems
Basic experimental “cavity” QED systems, introduction to the strong coupling regime and the brief overview of the group’s achievements during the last 20 years.

♦ Tools for fundamental cavity QED experiments
Basic experimental components and techniques which include manufacturing and tests of low-loss microwave mirrors, preparation and detection of circular Rydberg atoms, as well as the complete experimental assembly placed in a cryogenic environment.

♦ Quantum Non-Demolition measurement of light
Principle of our QND measurement of the photon number based on dispersive atom-field interaction and illustrated by experimental results on the atomic spin tomography and the progressive field collapse.

♦ Application of QND measurement of the photon number
Experimental results on the quantum Zeno effect and its theoretical explanation. Besides, the tomography of the cavity relaxation process obtained by means of the QND photon counting is presented.

♦ Complete time-resolved reconstruction of cavity field quantum states
Preparation of some quantum states of light, such as “Schrödinger’s cat” states and photon number (Fock) states, followed by their complete reconstruction using QND measurement and coherent field displacement ; Time evolution of the reconstructed states revealing their decoherence.

♦ Real-time quantum feedback stabilization of photon number states
Quantum feedback scheme prepares photon number (Fock) states of light and stabilizes them against decoherence. It is based on weak QND measurement, quantum state estimation and backaction onto the field which we realize either by coherent field injections into the cavity or by using individual resonant atoms able to emit or absorb single photons from the cavity.

♦ Two-cavity experiments
Outlook of some planned cavity QED experiments ranging from the active quantum feedback for the deterministic preparation of Fock states to the exploration of the non-local quantum physics in a two-cavity setup.

♦ Quantum Zeno dynamics
A series of frequent measurement can block the evolution of a quantum system, leading to the quantum Zeno effect. When the measurement has degenerate eigenvalues, the evolution of the system is restricted to a subspace of its Hilbert space, giving rise to the more spectacular quantum Zeno dynamics. We are working onto its implementation in a state-of-the-art cavity QED experiment, in construction at LKB.