Large-area $^{87}$Rb Bose-Einstein condensate in a clipped-Gaussian optical dipole trap

TL;DR

This paper reports the creation of large, elongated $^{87}$Rb Bose-Einstein condensates in a non-Gaussian, clipped-Gaussian optical dipole trap, revealing unique trap geometries and uniform density properties suitable for vortex shedding studies.

Contribution

The study introduces a novel non-Gaussian optical dipole trap formed by a clipped Gaussian beam, enabling large, elongated BECs with uniform density, which was not achieved with traditional Gaussian traps.

Findings

Generated large, elongated $^{87}$Rb BECs with specific dimensions.

Characterized the trap as having a quartic potential along the beam axis.

Observed uniform atom density within 10% over a significant central region.

Abstract

We demonstrate a production of large-area $^{87}$Rb Bose-Einstein condensates (BECs) using a non-Gaussian optical dipole trap (ODT). The ODT is formed by focusing a symmetrically truncated Gaussian laser beam and it is shown that the beam clipping causes the trap geometry elongated and flattened along the beam axis direction. In the clipped-Gaussian ODT, an elongated, highly oblate BEC of $^{87}$Rb is generated with length and width of approximately $470~\mu\textrm{m}$ and $130~\mu\textrm{m}$, respectively, where the condensate healing length is estimated to be $\xi\approx 0.25~\mu\textrm{m}$ at the trap center. The ODT is characterized to have a quartic trapping potential along the beam axis and the atom density of the condensate is uniform within 10% over $1000\xi$ in the central region. Finally, we discuss the prospect of conducting vortex shedding experiments using the elongated condensate.