Interference of a variable number of coherent atomic sources

TL;DR

This study investigates how the interference contrast of multiple independent atomic microcondensates decreases as their number increases, revealing a universal $1/\sqrt{N}$ decay law consistent with a random walk model.

Contribution

It demonstrates the $1/\sqrt{N}$ scaling law for interference contrast decay in ensembles of independent atomic sources, supported by experimental data and theoretical modeling.

Findings

Interference contrast decreases with increasing number of sources.

Experimental results agree with a random walk model prediction.

The $1/\sqrt{N}$ scaling law applies broadly to coherence decay.

Abstract

We have studied the interference of a variable number of independently created $m_F=0$ microcondensates in a CO$_{2}$-laser optical lattice. The observed average interference contrast decreases with condensate number N. Our experimental results agree well with the predictions of a random walk model. While the exact result can be given in terms of Kluyver's formula, for a large number of sources a $1/\sqrt{N}$ scaling of the average fringe contrast is obtained. This scaling law is found to be of more general applicability when quantifying the decay of coherence of an ensemble with N independently phased sources.