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H J Kimble

Publications and source records attributed to H J Kimble.

6 recordsLinked to original sources
PubMed2003

Experimental realization of a one-atom laser in the regime of strong coupling.

Conventional lasers (from table-top systems to microscopic devices) typically operate in the so-called weak-coupling regime, involving large numbers of atoms and photons; individual quanta have a negligible impact on the system dynamics. However, this is no longer the case when the system approaches the regime of strong coupling for which the number of atoms and photons can become quite small. Indeed, the lasing properties of a single atom in a resonant cavity have been extensively investigated theoretically. Here we report the experimental realization of a one-atom laser operated in the regime of strong coupling. We exploit recent advances in cavity quantum electrodynamics that allow one atom to be isolated in an optical cavity in a regime for which one photon is sufficient to saturate the atomic transition. The observed characteristics of the atom-cavity system are qualitatively different from those of the familiar many-atom case. Specifically, our measurements of the intracavity photon number versus pump intensity indicate that there is no threshold for lasing, and we infer that the output flux from the cavity mode exceeds that from atomic fluorescence by more than tenfold. Observations of the second-order intensity correlation function demonstrate that our one-atom laser generates manifestly quantum (nonclassical) light, typified by photon anti-bunching and sub-poissonian photon statistics.

Journal Article↗
PubMed2003

Efficient engineering of multiatom entanglement through single-photon detections.

We propose an efficient scheme to engineer multiatom entanglement by detecting cavity decay through single-photon detectors. In the special case of two atoms, this scheme is much more efficient than previous probabilistic schemes, and insensitive to randomness in the atom's position. More generally, the scheme can be used to prepare arbitrary superpositions of multiatom Dicke states without the requirements of high-efficiency detection and separate addressing of different atoms.

Journal Article↗
PubMed2003

Generation of nonclassical photon pairs for scalable quantum communication with atomic ensembles.

Quantum information science attempts to exploit capabilities from the quantum realm to accomplish tasks that are otherwise impossible in the classical domain. Although sufficient conditions have been formulated for the physical resources required to achieve quantum computation and communication, there is a growing understanding of the power of quantum measurement combined with the conditional evolution of quantum states for accomplishing diverse tasks in quantum information science. For example, a protocol has recently been developed for the realization of scalable long-distance quantum communication and the distribution of entanglement over quantum networks. Here we report the first enabling step in the realization of this protocol, namely the observation of quantum correlations for photon pairs generated in the collective emission from an atomic ensemble. The nonclassical character of the fields is demonstrated by the violation of an inequality involving their normalized correlation functions. Compared to previous investigations of non-classical correlations for photon pairs produced in atomic cascades and in parametric down-conversion, our experiment is distinct in that the correlated photons are separated by a programmable time interval (of about 400 nanoseconds in our initial experiments).

Journal Article↗
PubMed2003

State-insensitive cooling and trapping of single atoms in an optical cavity.

Single cesium atoms are cooled and trapped inside a small optical cavity by way of a novel far-off-resonance dipole-force trap, with observed lifetimes of 2-3 s. Trapped atoms are observed continuously via transmission of a strongly coupled probe beam, with individual events lasting approximately 1 s. The loss of successive atoms from the trap N>/=3-->2-->1-->0 is thereby monitored in real time. Trapping, cooling, and interactions with strong coupling are enabled by the trap potential, for which the center-of-mass motion is only weakly dependent on the atom's internal state.

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