13,564 research outputs found
Interaction of bimodal fields with few-level atoms in cavities and traps
The spectacular experimental results of the last few years in cavity quantum
electrodynamics and trapped ions research has led to very high level laboratory
performances. Such a stimulating situation essentially stems from two decisive
advancements. The first is the invention of reliable protocols for the
manipulation of single atoms. The second is the ability to produce desired
bosonic environments on demand. These progresses have led to the possibility of
controlling the form of the coupling between individual atoms and an arbitrary
number of bosonic modes. As a consequence, fundamental matter-radiation
interaction models like, for instance, the JC model and most of its numerous
nonlinear multiphoton generalizations, have been realized or simulated in
laboratory and their dynamical features have been tested more or less in
detail. This topical paper reviews the state of the art of the theoretical
investigations and of the experimental observations concerning the dynamical
features of the coupling between single few-level atoms and two bosonic modes.
In the course of the paper we show that such a configuration provides an
excellent platform for investigating various quantum intermode correlation
effects tested or testable in the cavity quantum electrodynamics and trapped
ion experimental realms. In particular we discuss a mode-mode correlation
effect appearing in the dynamics of a two-level atom quadratically coupled to
two bosonic modes. This effect, named parity effect, consists in a high
sensitivity to the evenness or oddness of the total number of bosonic
excitations.Comment: Topical Review. To appear on J. Mod. Op
Generation of pure, ionic entangled states via linear optics
In this paper, we propose a novel scheme to generate two-ion maximally
entangled states from either pure product states or mixed states using linear
optics. Our new scheme is mainly based on the ionic interference. Because the
proposed scheme can generate pure maximally entangled states from mixed states,
we denote it as purification-like generation scheme. The scheme does not need a
Bell state analyzer as the existing entanglement generation schemes do, it also
avoids the difficulty of synchronizing the arrival time of the two scattered
photons faced by the existing schemes, thus the proposed new entanglement
generation scheme can be implemented more easily in practice.Comment: 6 pages, 4 figure
Classical light vs. nonclassical light: Characterizations and interesting applications
We briefly review the ideas that have shaped modern optics and have led to
various applications of light ranging from spectroscopy to astrophysics, and
street lights to quantum communication. The review is primarily focused on the
modern applications of classical light and nonclassical light. Specific
attention has been given to the applications of squeezed, antibunched, and
entangled states of radiation field. Applications of Fock states (especially
single photon states) in the field of quantum communication are also discussed.Comment: 32 pages, 3 figures, a review on applications of ligh
Highly charged ions: optical clocks and applications in fundamental physics
Recent developments in frequency metrology and optical clocks have been based
on electronic transitions in atoms and singly charged ions as references. These
systems have enabled relative frequency uncertainties at a level of a few parts
in . This accomplishment not only allows for extremely accurate time
and frequency measurements, but also to probe our understanding of fundamental
physics, such as variation of fundamental constants, violation of the local
Lorentz invariance, and forces beyond the Standard Model of Physics. In
addition, novel clocks are driving the development of sophisticated technical
applications. Crucial for applications of clocks in fundamental physics are a
high sensitivity to effects beyond the Standard Model and Einstein's Theory of
Relativity and a small frequency uncertainty of the clock. Highly charged ions
offer both. They have been proposed as highly accurate clocks, since they
possess optical transitions which can be extremely narrow and less sensitive to
external perturbations compared to current atomic clock species. The selection
of highly charged ions in different charge states offers narrow transitions
that are among the most sensitive ones for a change in the fine-structure
constant and the electron-to-proton mass ratio, as well as other new physics
effects. Recent advances in trapping and sympathetic cooling of highly charged
ions will in the future enable high accuracy optical spectroscopy. Progress in
calculating the properties of selected highly charged ions has allowed the
evaluation of systematic shifts and the prediction of the sensitivity to the
"new physics" effects. This article reviews the current status of theory and
experiment in the field.Comment: 53 pages, 16 figures, submitted to RM
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