Single-photon cooling at the limit of trap dynamics: Maxwell's Demon near maximum efficiency

TL;DR

This paper demonstrates an efficient one-dimensional Maxwell's Demon cooling technique for atoms, achieving high phase-space compression and near-maximum efficiency limited only by particle dynamics.

Contribution

The authors experimentally realize a Maxwell's Demon cooling method with improved efficiency and phase-space compression, supported by a simple analytical model.

Findings

Transfer efficiency up to 2.2% achieved

Phase-space compression up to a factor of 350

15-fold improvement over previous work

Abstract

We demonstrate a general and efficient informational cooling technique for atoms which is an experimental realization of a one-dimensional Maxwell's Demon. The technique transfers atoms from a magnetic trap into an optical trap via a single spontaneous Raman transition which is discriminatively driven near each atom's classical turning point. In this way, nearly all of the atomic ensemble's kinetic energy in one dimension is removed. We develop a simple analytical model to predict the efficiency of transfer between the traps and provide evidence that the performance is limited only by particle dynamics in the magnetic trap. Transfer efficiencies up to 2.2% are reported. We show that efficiency can be traded for phase-space compression, and we report compression up to a factor of 350. Our results represent a 15-fold improvement over our previous demonstration of the cooling technique.