Phasor analysis of atom diffraction from a rotated material grating

Abstract

The strength of an atom-surface interaction is determined by studying atom diffraction from a rotated material grating. A phasor diagram is developed to interpret why diffraction orders are never completely suppressed when a complex transmission function due to the van der Waals interaction is present. We also show that atom-surface interactions can produce asymmetric diffraction patterns. Our conceptual discussion is supported by experimental observations with a sodium atom beam.Comment: 5 pages, 6 figures, submitted to PR

Dynamical local and nonlocal Casimir atomic phases

“…On the other hand, our more general result (6) allows for non-equilibrium [17,37] and non-stationary regimes which cannot be described by the more standard expression (8). Explicit results for the dynamical corrections to orderṙ k (t)/c were derived in Ref.…”

“…However, usual experimental conditions in Casimir interferometry [8][9][10] do not match this assumption, since the width of the atomic wave-packets are of the same order of the atom-surface distances. In this section, we present a derivation of the dynamical local and non local Casimir phases for finitewidth wave-packets.…”

“…Fortunately, this divergence can be easily cured, since such contributions lead to quickly oscillating complex exponentials which in fact barely affect the average vdW phase [8,10]. To make our argument more precise, we reintroduce these exponentials in our derivation of the average dynamical phase Φ DP 12 (T ):…”

“…Considering 87 Rb atoms and a wave-packet width w = 40 nm (and thus z 0 = w 0 /2 = 20 nm) compatible with the parameters used in the Casimir experiments [8][9][10] for the wave-packets, one obtains a DP phase φ DP 12 w 3 × 10 −6 rad, corresponding to an enhancement of roughly one order of magnitude.…”

“…There is a growing interest in developing atom interferometers able to probe surface interactions. Measurements of the van der Waals atom-surface interaction with standard atom interferometry have already been achieved [8][9][10], while optical-lattice atom interferometry offers even more promising perspectives to measure the Casimir-Polder interaction in the long-distance regime [11].…”