Cavity QED with Multiple Hyperfine Levels

We calculate the weak-driving transmission of a linearly polarized cavity mode strongly coupled to the D2 transition of a single Cesium atom. Results are relevant to future experiments with microtoroid cavities, where the single-photon Rabi frequency g exceeds the excited-state hyperfine splittings, and photonic bandgap resonators, where g is greater than both the excited- and ground-state splitting.Comment: 6 pages, 10 figure

Zener Disaccommodation In Dilute F.C.C. Co-Ti Alloys

The magnetic Dis accommodation, i.e., the time dependence of the low field magnetic permeability, was investigated in cobalt base alloys containing 0-5.1 at.% (0-4.2 wt.%) titanium in the temperature range 400-700°C. A strong temperature dependence of the Dis accommodation observed in the range 430-530°C could be accounted for predominantly by a single first order relaxation process. Analyzing the data in terms of (a) a single exponential relaxation, (b) a lognormal distribution of relaxation times, and (c) a sum of exponential relaxations, it was shown that the relaxation strength varies as the square of the titanium concentration and that the relaxation is characterized by an activation enthalpy of 69 ± 1 kcal/mole and a τ0 of the order of 10-16 sec. The Dis accommodation was attributed to the reorientation of substitutional solute atom (titanium) pairs. From the temperature dependence of the relaxation strength the binding energy of Ti atom pairs was determined to be 0.17 ± 0.08 eV. © 1968

Trapped atoms in cavity QED: coupling quantized light and matter

On the occasion of the hundredth anniversary of Albert Einstein's annus mirabilis, we reflect on the development and current state of research in cavity quantum electrodynamics in the optical domain. Cavity QED is a field which undeniably traces its origins to Einstein's seminal work on the statistical theory of light and the nature of its quantized interaction with matter. In this paper, we emphasize the development of techniques for the confinement of atoms strongly coupled to high-finesse resonators and the experiments which these techniques enable

Observation of the Vacuum-Rabi Spectrum for One Trapped Atom

The transmission spectrum for one atom strongly coupled to the field of a high-finesse optical resonator is observed to exhibit a clearly resolved vacuum-Rabi splitting characteristic of the normal modes in the eigenvalue spectrum of the atom-cavity system. A new Raman scheme for cooling atomic motion along the cavity axis enables a complete spectrum to be recorded for an individual atom trapped within the cavity mode, in contrast to all previous measurements in cavity QED that have required averaging over many atoms.Comment: 5 pages with 4 figure

Cavity QED with Single Atoms and Photons

Recent experimental advances in the field of cavity quantum electrodynamics (QED) have opened new possibilities for control of atom-photon interactions. A laser with "one and the same atom" demonstrates the theory of laser operation pressed to its conceptual limit. The generation of single photons on demand and the realization of cavity QED with well defined atomic numbers N = 0, 1, 2,... both represent important steps toward realizing diverse protocols in quantum information science. Coherent manipulation of the atomic state via Raman transitions provides a new tool in cavity QED for in situ monitoring and control of the atom-cavity system. All of these achievements share a common point of departure: the regime of strong coupling. It is thus interesting to consider briefly the history of the strong coupling criterion in cavity QED and to trace out the path that research has taken in the pursuit of this goal

Interstitial Solute Trapping In Irradiated And Quenched Iron

The interaction of interstitial carbon and nitrogen solutes with defects produced by low temperature neutron irradiation and by quenching was studied in high purity and Ferrovac E iron. Magnetic Dis accommodation techniques were applied to determine the interstitial solute content after irradiation and upon annealing. Doses of about 1017 neutrons/cm2 caused the trapping of about 20 ppm (atomic) interstitial solutes at 65 (carbon) and 40°C (nitrogen). Trapping of carbon in a Ferrovac E iron alloy occurred during a fast quench from 880°C. After trapping, the interstitial solutes reappeared in solid solution at 300 (carbon, neutron irradiation), 200 (nitrogen, neutron irradiation), and 620°C (carbon, quenching). Various possibilities for the defect traps were considered and it was concluded that trapping of the interstitial solutes occurred at iron interstitial clusters after neutron irradiation and at vacancy type defects after quenching. Copyright © 1968 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinhei

Availability of soil mutualists may not limit non‐native Acacia invasion but could increase their impact on native soil communities

The availability of compatible mutualistic soil microbes could influence the invasion success of non-native plant species. Specifically, there may be spatial variation in the distribution of compatible microbes, and species-specific variation in plant host ability to associate with available microbes. Although either or both factors could promote or limit invasion, the scale over which most studies are conducted makes it difficult to examine these two possibilities simultaneously. However, this is critical to identifying a role of soil microbes in invasion. A series of recent research projects focused on interactions between Australian Acacia and nitrogen-fixing bacteria (rhizobia) at multiple spatial scales, from the local to the inter-continental, has allowed us to evaluate this question. Collectively, this research reveals that nodulation, performance and rhizobial community composition are all broadly similar across spatial scales and differentially invasive species. Synthesis and applications. We argue that current research provides convincing evidence that interactions with rhizobia do not determine invasion success in Acacia, but instead highlights key knowledge gaps that remain unfilled. Importantly, the ease with which non-native Acacia species form mutualistic associations with rhizobia, regardless of invasive status, highlights the critical need to understand the impacts of all non-native Acacia on native soil communities