Comparison of time profiles for the magnetic transport of cold atoms

TL;DR

This paper compares various time profiles for transporting cold sodium atoms in a magnetic trap, identifying a smooth error function-based profile that optimizes speed while minimizing atom loss and heating.

Contribution

It introduces an analytically defined smooth transport profile that balances transport duration and atom preservation, supported by experimental and numerical analysis.

Findings

The error function profile reduces transport time.

Smooth profiles limit atom losses and heating.

Trade-off between trap depth and Majorana flips explained.

Abstract

We have compared different time profiles for the trajectory of the centre of a quadrupole magnetic trap designed for the transport of cold sodium atoms. Our experimental observations show that a smooth profile characterized by an analytical expression involving the error function minimizes the transport duration while limiting atom losses and heating of the trapped gas. Using numerical calculations of single atom classical trajectories within the trap, we show that this observation can be qualitatively interpreted as a trade-off between two types of losses: finite depth of the confinement and Majorana spin flips.