Optics and Interferometry withNa2Molecules

Abstract

We have produced an intense, pure beam of sodium molecules (Naz) by using light forces to separate the atomic and molecular species in a seeded supersonic beam. We used diffraction from a microfabricated grating to study the atomic and molecular sodium in the beam. Using three of these gratings, we constructed a molecule interferometer with fully separated beams and high contrast fringes.We measured both the real and imaginary parts of the index of refraction of neon gas for Na& molecule de Broglie waves by inserting a gas cell in one arm of the interferometer.PACS numbers: 03.75.b, 07.77.Gx, 34.20.Gj Quantum mechanical treatment of the center-of-mass motion of increasingly complex systems is an important theme in modern physics. This issue is manifest theoretically in studies of the transition from quantum through mesoscopic to classical regimes and experimentally in efforts to coherently control and manipulate the external spatial coordinates of complex systems (e.g., matter wave optics and interferometry).Recently, matter wave optics and interferometry have been extended to atoms with the many techniques for the coherent manipulation of the external degrees of freedom of atoms constituting a new field called atom optics [1]. The present work extends and develops techniques of atom optics into the domain of moleculessystems characterized by many degenerate and nondegenerate internal quantum states. Whereas internal state coherences in complex molecules have long been cleverly manipulated in spectroscopy in both the radio [2] and optical frequency domains [3,4], here we coherently manipulate exclusively the center-of-mass motion [5]. This work, which culminates in the use of a molecule interferometer with spatially separated beams to determine hitherto unmeasurable molecular properties, demonstrates the applicability of molecular interferometers to precision measurements in molecular physics, some of which may have applications to fundamental physics experiments using specific molecules [6].Our experiment combines several techniques from atom optics to make and use a molecule interferometer whose paths are well separated in position and momentum. Using an incident supersonic beam containing both Na atoms and dimers (Naq), we apply resonant light forces to selectively remove the Na atoms, leaving a pure Na& beam. We then use nanofabricated diffraction gratings, first to study the characteristics of the molecular beam and subsequently as coherent beam splitters to make a molecule interferometer with high contrast fringes.Finally, we insert a gas cell in one path of the separated beam interferometer and measure the complex index of refraction for Na~de Broglie waves in Ne gas. This provides new information on the long-range part of the Na~-Ne potential.The beam of sodium atoms and dimers was produced in a seeded supersonic expansion using either argon or krypton as the carrier gas. By heating the Na reservoir to 800'C (Na vapor pressure -300 torr), we were able to enhance the population of sodium dimers in the b...

Action principle formulation for the motion of extended bodies in general relativity

“…Our formulation of action principle for extended body may facilitate and prompt further investigations in the important and emerging area of interface between quantum and gravitational realms [15]. Particularly, the ongoing experiments in atomic [16], molecular [17] and Bose-Einstein condensate interferometry [18] hold promise for experimentally testing the new gravitational phase shifts that will be obtained in the present letter.We envision an extended rigid body as a thin world tube in spacetime and its thickness is small compared to the scale over which curvature varies. We would further assume that there are no external or internal forces acting on this body apart from the gravitational field in which it is propagating.…”

“…Our formulation of action principle for extended body may facilitate and prompt further investigations in the important and emerging area of interface between quantum and gravitational realms [15]. Particularly, the ongoing experiments in atomic [16], molecular [17] and Bose-Einstein condensate interferometry [18] hold promise for experimentally testing the new gravitational phase shifts that will be obtained in the present letter.…”

“…And above all we have found the action for such a body which we have also used to compute the gravitational phase shifts in its quantum wavefunction due to the multipoles. We hope that the new gravitationally induced phase shifts would be measured in future interferometry experiments based on atomic, molecular and Bose-Einstein condensates [16][17][18]. Our novel algorithm also yields modifications to the geodesic equation which, with present day high precision astronomical observations yielding multipole moments of planetary or stellar bodies,can be applied to obtain aberrations in their orbits.…”

Decoherence in a Talbot–Lau interferometer: the influence of molecular scattering

“…Any increase in size and complexity generally opens new decoherence channels, and for large molecules one can think of many interactions with the environment, either by scattered radiation [6], by collisions with particles [7], by an interaction with fluctuating quasi-static electro-magnetic fields [8] or even by the interaction with gravitational waves [9].…”

Current-voltage relation for a field ionizing He beam detector

“…1,2 Applications that extract the coherent fraction from such beams in one transverse dimension have been carried out, [3][4][5][6] and recent transverse dimensional coherent experiments have been accomplished. 7,8 Spatial filtering renders the coherent flux available in such experiments many orders of magnitude lower than the incoherent flux used in conventional helium scattering experiments.…”