Atom counting in ultra-cold gases using photoionisation and ion detection

TL;DR

This paper demonstrates a method for accurately counting ultra-cold atoms using photoionisation and ion detection, enabling precise measurement of atom numbers and quantum statistics with current technology.

Contribution

It introduces a practical detection scheme for ultra-cold atoms that achieves high accuracy and can probe quantum statistical properties and single atom detection.

Findings

Counting accuracy better than N^{-1/2} for thousands of atoms.

Ability to probe sub-Poissonian number statistics.

Potential for high-resolution single atom detection.

Abstract

We analyse photoionisation and ion detection as a means of accurately counting ultra-cold atoms. We show that it is possible to count clouds containing many thousands of atoms with accuracies better than $N^{-1/2}$ with current technology. This allows the direct probing of sub-Poissonian number statistics of atomic samples. The scheme can also be used for efficient single atom detection with high spatio-temporal resolution. All aspects of a realistic detection scheme are considered, and we discuss experimental situations in which such a scheme could be implemented.