Laser cooling and trapping
TL;DR: In this article, the basic physical effects leading to radiation-induced forces are reviewed and a simple derivation of the mathematical expressions for the classical light forces is given, and the influence of quantum fluctuations is demonstrated and the possibilities for trapping neutral particles are discussed.
Abstract: The basic physical effects leading to radiation-induced forces are reviewed. A simple derivation of the mathematical expressions for the classical light forces is given. The influence of quantum fluctuations is demonstrated and the possibilities for trapping neutral particles are discussed. Two recent successful laser cooling and trapping experiments are described to illustrate the applications of the basic principles.
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TL;DR: Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases and have found numerous experimental applications, opening up the way to important breakthroughs as mentioned in this paper.
Abstract: Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases. They have found numerous experimental applications, opening up the way to important breakthroughs. This review broadly covers the phenomenon of Feshbach resonances in ultracold gases and their main applications. This includes the theoretical background and models for the description of Feshbach resonances, the experimental methods to find and characterize the resonances, a discussion of the main properties of resonances in various atomic species and mixed atomic species systems, and an overview of key experiments with atomic Bose-Einstein condensates, degenerate Fermi gases, and ultracold molecules.
2,642 citations
TL;DR: Rydberg atoms with principal quantum number $n⪢1$ have exaggerated atomic properties including dipole-dipole interactions that scale as ${n}^{4}$ and radiative lifetimes that scale at least{n}−3}$ as mentioned in this paper, and it was proposed a decade ago to implement quantum gates between neutral atom qubits.
Abstract: Rydberg atoms with principal quantum number $n⪢1$ have exaggerated atomic properties including dipole-dipole interactions that scale as ${n}^{4}$ and radiative lifetimes that scale as ${n}^{3}$. It was proposed a decade ago to take advantage of these properties to implement quantum gates between neutral atom qubits. The availability of a strong long-range interaction that can be coherently turned on and off is an enabling resource for a wide range of quantum information tasks stretching far beyond the original gate proposal. Rydberg enabled capabilities include long-range two-qubit gates, collective encoding of multiqubit registers, implementation of robust light-atom quantum interfaces, and the potential for simulating quantum many-body physics. The advances of the last decade are reviewed, covering both theoretical and experimental aspects of Rydberg-mediated quantum information processing.
2,156 citations
TL;DR: In this article, the authors review recent developments in the physics of ultracold atomic and molecular gases in optical lattices and show how these systems may be employed as quantum simulators to answer some challenging open questions of condensed matter, and even high energy physics.
Abstract: We review recent developments in the physics of ultracold atomic and molecular gases in optical lattices. Such systems are nearly perfect realisations of various kinds of Hubbard models, and as such may very well serve to mimic condensed matter phenomena. We show how these systems may be employed as quantum simulators to answer some challenging open questions of condensed matter, and even high energy physics. After a short presentation of the models and the methods of treatment of such systems, we discuss in detail, which challenges of condensed matter physics can be addressed with (i) disordered ultracold lattice gases, (ii) frustrated ultracold gases, (iii) spinor lattice gases, (iv) lattice gases in “artificial” magnetic fields, and, last but not least, (v) quantum information processing in lattice gases. For completeness, also some recent progress related to the above topics with trapped cold gases will be discussed. Motto: There are more things in heaven and earth, Horatio, Than are dreamt of in your...
1,535 citations
01 May 2009
TL;DR: Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases and have found numerous experimental applications, opening up the way to important breakthroughs as mentioned in this paper.
Abstract: Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases. They have found numerous experimental applications, opening up the way to important breakthroughs. This review broadly covers the phenomenon of Feshbach resonances in ultracold gases and their main applications. This includes the theoretical background and models for the description of Feshbach resonances, the experimental methods to find and characterize the resonances, a discussion of the main properties of resonances in various atomic species and mixed atomic species systems, and an overview of key experiments with atomic Bose-Einstein condensates, degenerate Fermi gases, and ultracold molecules.
1,531 citations
TL;DR: In this paper, an introduction to the physics of ultracold bosonic atoms in optical lattices is given and an overview of the theoretical and experimental advances to date is provided.
Abstract: Matter waves inside periodic potentials are well known from solid-state physics, where electrons interacting with a crystal lattice are considered. Atomic Bose-Einstein condensates inside light-induced periodic potentials (optical lattices) share many features with electrons in solids, but also with light waves in nonlinear materials and other nonlinear systems. Generally, atom-atom interactions in Bose-Einstein condensates lead to rich and interesting nonlinear effects. Furthermore, the experimental control over the parameters of the periodic potential and the condensate make it possible to enter regimes inaccessible in other systems. In this review, an introduction to the physics of ultracold bosonic atoms in optical lattices is given and an overview of the theoretical and experimental advances to date.
1,346 citations
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TL;DR: The confinement and cooling of an optically dense cloud of neutral sodium atoms by radiation pressure was reported, provided by three retroreflected laser beams propagating along orthogonal axes, with a weak magnetic field used to distinguish between the beams.
Abstract: We report the confinement and cooling of an optically dense cloud of neutral sodium atoms by radiation pressure. The trapping and damping forces were provided by three retroreflected laser beams propagating along orthogonal axes, with a weak magnetic field used to distinguish between the beams. We have trapped as many as ${10}^{7}$ atoms for 2 min at densities exceeding ${10}^{11}$ atoms ${\mathrm{cm}}^{\ensuremath{-}3}$. The trap was \ensuremath{\simeq}0.4 K deep and the atoms, once trapped, were cooled to less than a millikelvin and compacted into a region less than 0.5 mm in diameter.
1,402 citations
TL;DR: Expressions are derived for the probability p(n) that n photons are emitted in a given time in the steady state by a two-level atom, when it is placed in a resonant, coherent, exciting field, which is shown to be narrower than Poissonian.
Abstract: Expressions are derived for the probability p(n) that n photons are emitted in a given time in the steady state by a two-level atom, when it is placed in a resonant, coherent, exciting field. The distribution p(n) is shown to be narrower than Poissonian. The ratio [〈(Δn)2〉 − 〈n〉]/〈n〉 is negative and has an absolute maximum value of 3/4. The possibility of observing the sub-Poissonian statistics is discussed briefly.
960 citations
TL;DR: The first observation of optically trapped atoms is reported, with estimates that about 500 atoms are confined in a volume of about ${10}^{3}$ \ensuremath{\mu}$ m3 at a density of about £10^{11}$-${10]^{12}$ and in good quantitative agreement with theoretical expectations.
Abstract: We report the first observation of optically trapped atoms Sodium atoms cooled below ${10}^{\ensuremath{-}3}$ K in "optical molasses" are captured by a dipole-force optical trap created by a single, strongly focused, Gaussian laser beam tuned several hundred gigahertz below the ${D}_{1}$ resonance transition We estimate that about 500 atoms are confined in a volume of about ${10}^{3}$ \ensuremath{\mu}${\mathrm{m}}^{3}$ at a density of ${10}^{11}$-${10}^{12}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ Trap lifetimes are limited by background pressure to several seconds The observed trapping behavior is in good quantitative agreement with theoretical expectations
793 citations
TL;DR: In this paper, the basic theory of the mechanical action of light in resonant interaction with atoms is reviewed. But the main application is laser cooling, but the approach is applicable to a broader range of phenomena.
Abstract: This paper reviews the basic theory of the mechanical action of light in resonant interaction with atoms. At present the main application is laser cooling, but the approach is applicable to a broader range of phenomena. It is based on an adiabatic elimination philosophy, which turns out to give the lowest-order quantum corrections to the behavior found when the photon momentum goes to zero. Hence it is called a semiclassical theory. In this manner a subjective but consistent approach can be presented; other treatments are incorporated or mentioned at the appropriate places. Both the classical and the quantum-mechanical approach are discussed. Those readers who wish to obtain only a heuristic overview of the phenomena can concentrate on Sec. III, which treats both the photon momentum effects and their connection with photon counting statistics. The detailed theoretical treatment utilizes Wigner functions and Fokker-Planck techniques. The ensuing theory is applied both to the cooling of free particles and trapped ones. The paper ends with an extensive bibliography, where the author lists most papers of interest for research into the mechanical manifestations of light. For completeness, many papers are included that are not explicitly mentioned in the text.
511 citations
TL;DR: It is proved that a small dielectric particle cannot be trapped by using only the scattering force of optical radiation pressure, and the implications of the theorem for recent proposals for the optical trapping of neutral atoms are discussed.
Abstract: We prove an optical radiation Earnshaw theorem: A small dielectric particle cannot be trapped by using only the scattering force of optical radiation pressure. A corollary is that the gradient or dipole force is necessary to any successful optical trap. We discuss the implications of the theorem for recent proposals for the optical trapping of neutral atoms.
167 citations