Three-dimensional atom localization from spatial interference in a double two-level atomic system

Abstract

We propose a efficient scheme for high-precision three-dimensional (3D) atom localization via spatial interference in a generic double two-level atomic system driven by a weak probe field and three mutually perpendicular standing-wave fields. Because the spatial interference originates from the position-dependent atom-field interaction, the position information of the atom can be obtained by the measurement of the atom population. We find that the precision of 3D atom localization in volumes depends sensitively on the frequency detuning and the phase shifts associated with the standing-wave fields. Interestingly enough, we show that adjusting the frequency detuning and phase shifts can lead to a redistribution of the atoms and a significant change in the visibility of the interference pattern. As a result, the atom can be localized in volumes that are substantially smaller than a cubic optical wavelength.