Abstract

Atom interferometry has been used for several years as an effective tool to realize both fundamental experiments and high precision measurements. In this communication, we report the experimental realization of a slow atom polarization interferometer. The demonstrated interferences are the atomic analogs of those obtained with polarized light crossing crystal plates. It is also an extension of the Stern-Gerlach Atom Interferometry previously developped in our laboratory [1] for rapid metastable hydrogen atoms. In the present work, Cesium atoms are released from an optical molasses at a temperature of 5 μK. During the subsequent free fall phase, atoms are first optically pumped in the F=4, m_F = 4 sublevel. This first step parallels the polarization of light. After this step, atoms are polarized along their vertical trajectory while the definition of a quantization axis is ensured by a weak static vertical field. A pulsed transverse homogeneous magnetic field (~10 pT) is then applied during a few ten ps. Switching times (~0.1 μs)are such that adiabatic following is avoided. This phase parallels the crossing of the crystal plate. State-selective detection is then realized by means of a longitudinal Stern-Gerlach effect [2]. As shown in figure 1, scanning the pulse duration yields interferences. This experimental outcome is a manifestation of the Scalar Bohm-Aharonov effect [1]. On a more practical viewpoint, it calls for further developments in the spirit of its photonic counterpart. Among other possibilities, addition of inhomogeneous fields will allow the realization of high-precision inertial sensors.

© 1998 IEEE