Competition effects of multiple quantum paths in an atom interferometer

TL;DR

This paper investigates how multiple quantum paths in a Raman atom interferometer compete and affect interference contrast, revealing oscillations due to phase competition and methods to optimize contrast.

Contribution

It experimentally demonstrates the competition effect among multiple quantum paths in a Raman atom interferometer and shows how to optimize interference contrast by suppressing phase competition.

Findings

Contrast oscillates periodically with phase or interrogation time.

Multiple quantum paths arise from imperfect population transfer.

Contrast can be optimized by suppressing phase competition.

Abstract

We present an observation of competition effect among multiple quantum paths in a Raman-type Mach-Zehnder atom interferometer. By measuring the contrast of interference fringes, the competition effect among multiple interference paths is experimentally investigated. Due to the phase competition, the contrast periodically oscillates when modulating either the phase or the interrogation time between Raman pulses. The multiple quantum paths form because of the imperfect population transfer efficiency in stimulated Raman transitions, and are verified by modulating the duration of Raman pulses. The contrast could be optimized by suppressing the phase competition.