Bose-Einstein condensate of metastable helium for quantum correlation experiments

TL;DR

This paper reports the successful creation of a Bose-Einstein condensate of metastable helium-4 and introduces a high-resolution detection system designed for quantum correlation experiments, enabling exploration of fundamental quantum phenomena.

Contribution

The study demonstrates the first Bose-Einstein condensation of metastable helium-4 combined with a novel detection system for quantum correlation measurements.

Findings

Achieved Bose-Einstein condensation of metastable helium-4 with ~10^6 atoms.

Developed an ultrafast delay-line detector for high-resolution atomic correlation detection.

Set the stage for direct observation of momentum entanglement and quantum correlations.

Abstract

We report on the realization of Bose-Einstein condensation of metastable helium-4. After exciting helium to its metastable state in a novel pulse-tube cryostat source, the atomic beam is collimated and slowed. We then trap several 10^8 atoms in a magneto-optical trap. For subsequent evaporative cooling, the atoms are transferred into a magnetic trap. Degeneracy is achieved with typically a few 10^6 atoms. For detection of atomic correlations with high resolution, an ultrafast delay-line detector has been installed. Consisting of four quadrants with independent readout electronics that allow for true simultaneous detection of atoms, the detector is especially suited for quantum correlation experiments that require the detection of correlated subsystems. We expect our setup to allow for the direct demonstration of momentum entanglement in a scenario equivalent to the Einstein-Podolsky-Rosen gedanken experiment. This will pave the way to matter-wave experiments exploiting the peculiarities of quantum correlations.