Optics and interferometry with matter waves is the art of coherently manipulating the translational motion of particles like neutrons, atoms and molecules. Coherent atom optics is an extension of techniques that were developed for manipulating \emph{internal} quantum states. Applying these ideas to translational motion required the development of techniques to localize atoms and transfer population coherently between distant localities. In this view position and momentum are (continuouse) quantum mechanical degree of freedom analogous to discrete internal quantum states. In our contribution we start with an introduction into matter-wave optics in section 1, discuss coherent atom optics and atom interferometry techniques for molecular beams in section 2 and for trapped atoms in section 3. In section 4 we then describe tools and experiments that allow us to probe the evolution of quantum states of many-body systems by atom interference.
Optics and interferometry with matter waves is the art of coherently manipulating the translational motion of particles like neutrons, atoms and molecules. Coherent atom optics is an extension of techniques that were developed for manipulating \emph{internal} quantum states. Applying these ideas to translational motion required the development of techniques to localize atoms and transfer population coherently between distant localities. In this view position and momentum are (continuouse) quantum mechanical degree of freedom analogous to discrete internal quantum states. In our contribution we start with an introduction into matter-wave optics in section 1, discuss coherent atom optics and atom interferometry techniques for molecular beams in section 2 and for trapped atoms in section 3. In section 4 we then describe tools and experiments that allow us to probe the evolution of quantum states of many-body systems by atom interference.
Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic clocks. Atom interferometry is now reaching maturity as a powerful art with many applications in modern science. In this review the basic tools for coherent atom optics are described including diffraction by nanostructures and laser light, three-grating interferometers, and double wells on atom chips. Scientific advances in a broad range of fields that have resulted from the application of atom interferometers are reviewed. These are grouped in three categories: (i) fundamental quantum science, (ii) precision metrology, and (iii) atomic and molecular physics. Although some experiments with Bose-Einstein condensates are included, the focus of the review is on linear matter wave optics, i.e., phenomena where each single atom interferes with itself.
Matter wave optics has a long tradition spanning over many decades starting with electron and ion optics. These techniques now find commercial applications in microscopy and lithography. Neutron optics contributed many beautiful experiments that tested many fundamental principles in quantum mechanics. Over the last decade the field of atom optics has been developed. In particular the availability of narrowband tunable laser sources has opened up the addressing of the internal electronic degrees of freedom of the atoms and as a result, the manipulation of their trajectories. The dissipative nature of the atom light interaction is used for laser cooling methods e.g. to collimate atomic beams to a high brightness whereas the dispersive nature of the interaction is used to realize different atom optical components like lenses, beam-splitters and mirrors. Consequently atom optics is now at a stage where applications of those elements in more complex systems are studied. An overview of recent developments is given. This includes atom interferometry and atom lithography experiments and experiments with a quasi 2D gas of ultra cold atoms in planar waveguides. Future directions and applications are outlined.
We describe the state of the art in preparing, manipulating and detecting coherent molecular matter. We focus on experimental methods for handling the quantum motion of compound systems from diatomic molecules to clusters or biomolecules.Molecular quantum optics offers many challenges and innovative prospects: already the combination of two atoms into one molecule takes several well-established methods from atomic physics, such as for instance laser cooling, to their limits. The enormous internal complexity that arises when hundreds or thousands of atoms are bound in a single organic molecule, cluster or nanocrystal provides a richness that can only be tackled by combining methods from atomic physics, chemistry, cluster physics, nanotechnology and the life sciences.We review various molecular beam sources and their suitability for matter-wave experiments. We discuss numerous molecular detection schemes and give an overview over diffraction and interference experiments that have already been performed with molecules or clusters.Applications of de Broglie studies with composite systems range from fundamental tests of physics up to quantum-enhanced metrology in physical chemistry, biophysics and the surface sciences.Nanoparticle quantum optics is a growing field, which will intrigue researchers still for many years to come. This review can, therefore, only be a snapshot of a very dynamical process.
Abstract The past few decades have seen dramatic progress in our ability to manipulate and coherently control matter-waves. Although the duality between particles and waves has been well tested since de Broglie introduced the matter-wave analog of the optical wavelength in 1924, manipulating atoms with a level of coherence that enables one to use these properties for precision measurements has only become possible with our ability to produce atomic samples exhibiting temperatures of only a few millionths of a degree above absolute zero. Since the initial experiments a few decades ago, the field of atom optics has developed in many ways, with both fundamental and applied significance. The exquisite control of matter waves offers the prospect of a new generation of force sensors exhibiting unprecedented sensitivity and accuracy, for applications from navigation and geophysics to tests of general relativity. Thanks to the latest developments in this field, the first commercial products using this quantum technology are now available. In the future, our ability to create large coherent ensembles of atoms will allow us an even more precise control of the matter-wave and the ability to create highly entangled states for non-classical atom interferometry.
Matter–wave interferometry dates from the inception of quantum mechanics, i.e., the early electron diffraction experiments. More recent neutron interferometry experiments have yielded new insights into many fundamental aspects of quantum mechanics. Presently, atom interferometry has been demonstrated and holds promise as a new field of optics – matter–wave optics. This field is particularly interesting since the potential sensitivity of matter–wave interferometers far exceeds that of their light-wave or ‘photon’ antecedents. In this chapter we consider the physics of light-induced forces on the center-of-mass motion of atoms and their application to atom optics (Fig. 17.1). The most obvious being the recoil associated with the emission and absorption of light. This ‘radiation pressure’ is the basis for laser induced cooling. Another very important mechanical effect is the gradient force due to, e.g., transverse variation in the laser beam. These, essentially semiclassical, forces are useful in guiding and trapping neutral atoms. After considering the basic forces which allow us to cool, guide, and trap atoms, we turn to the optics of atomic center-of-mass de Broglie waves, i.e., atom optics. In keeping with the spirit of the present text, we will focus on the quantum limits to matter–wave interferometry. An analysis of a matter–wave gyro in an obvious extension of the laser gyro and the similarity and relative merits of the two will be compared and contrasted. Finally we derive the “recoil limit” to laser cooling; and show that it is possible to supersede this limit via atomic coherence effects.
The general goal of our research is the generation, manipulation, and characterization of coherent and nonclassical matter-wave sources. The research has both a theoretical and an experimental component. Theoretical achievements include the use of nonlinear atom optical techniques to generate beams of entangled atoms and squeezed atomic beams from Bose-Einstein condensates, as well as the generation of entangled atom-photon pairs, the extension of the ideas bosonic atom optics to the nonlinear atom optics to fermionic atoms and to boson-fermion mixtures. We have also started to analyze how the combination of these developments can be applied to the realization and manipulation of molecular fields of tailored quantum statistics. On the experimental side we have worked with Cs atoms in optical lattices to implement qubits, quantum gates and circuits. We have demonstrated trapping in deep 3D lattices initialization by sideband cooling and single-qubit control. In a second project we have used optical probes to implement continuous weak measurements of collective observables in an atomic ensemble. We have developed a detailed understanding of Faraday measurements of atomic spins, and a novel scheme to probe the pseudospin associated with the atomic clock transition.