Light shifts in atomic Bragg diffraction

TL;DR

This paper investigates how the shape of laser pulses affects light-induced phase shifts in atomic Bragg diffraction, revealing that Gaussian pulses suppress the shift while box-shaped pulses enhance it, with implications for precision measurements.

Contribution

It provides analytical and numerical analysis showing the dependence of light shifts on pulse shape in atomic Bragg diffraction, a novel insight for quantum optics.

Findings

Gaussian pulses suppress the phase shift proportional to the inverse Doppler frequency cubed.

Box-shaped pulses cause a phase shift twice as large as in Raman diffraction.

Analytical expressions and numerical simulations confirm the pulse shape dependence.

Abstract

Bragg diffraction of an atomic wave packet in a retroreflective geometry with two counterpropagating optical lattices exhibits a light shift induced phase. We show that the temporal shape of the light pulse determines the behavior of this phase shift: In contrast to Raman diffraction, Bragg diffraction with Gaussian pulses leads to a significant suppression of the intrinsic phase shift due to a scaling with the third power of the inverse Doppler frequency. However, for box-shaped laser pulses, the corresponding shift is twice as large as for Raman diffraction. Our results are based on approximate, but analytical expressions as well as a numerical integration of the corresponding Schr\"odinger equation.