Journal of Physics B Atomic Molecular and Optical Physics

Sub-Doppler deep-cooled bosonic and fermionic isotopes of potassium in a compact 2D+–3D MOT set-up

Vandna Gokhroo, G Rajalakshmi, Raghavan K. Easwaran, C. S. Unnikrishnan

Published May 20, 2011• 48 citations

Abstract

We report the sub-Doppler deep-cooled three-dimensional magneto-optical trap (3D MOT) of the fermionic 40K and bosonic 39K isotopes of potassium loaded by a very compact 2D+ MOT with a novel optical design feature. The set-up is meant for studies on the quantum dynamics of a few fermionic and bosonic atoms in an optical dipole trap near and well within quantum degeneracy. The loading rate and atom numbers achieved in the compact simple set-up are comparable to those in the previous set-ups with more elaborate vacuum design. We attained relatively low temperatures of 34 and 30 µK for 39K and 40K after the sub-Doppler cooling process.

DOI: 10.1088/0953-4075/44/11/115307

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Journal of Physics B Atomic Molecular and Optical Physics

Sub-Doppler deep-cooled bosonic and fermionic isotopes of potassium in a compact 2D+–3D MOT set-up

Vandna Gokhroo, G Rajalakshmi, Raghavan K. Easwaran, C. S. Unnikrishnan

Published May 20, 2011• 48 citations

Publisher

Abstract

DOI: 10.1088/0953-4075/44/11/115307

Related papers

Magnetic trapping of an ultracold 39K-40K mixture with a versatile potassium laser system

Mateusz Bocheński, Jakub Dobosz, Mariusz Semczuk

We present a dual isotope magneto-optical trap (MOT), simultaneous sub-Doppler laser cooling, and magnetic trapping of a spin-polarized 39K-40K Bose-Fermi mixture realized in a single-chamber setup with an unenriched potassium dispenser as the source of atoms. We are able to magnetically confine more than 2.2 × 105 fermions (F = 9/2 , m F = 9/2) and 1.4 × 107 bosons (F = 2 , m F = 2) with a lifetime exceeding 1.2 s. For this work, we have developed a versatile laser tailored for sub-Doppler cooling of all naturally occurring potassium isotopes and their mixtures. This laser system incorporates innovative features, such as the capability to select an isotope by activating or deactivating specific acousto-optic modulators that control the light seeding tapered amplifiers. Switching between isotopes takes ∼1 µs without any mechanical adjustment of the components.We present a dual isotope magneto-optical trap (MOT), simultaneous sub-Doppler laser cooling, and magnetic trapping of a spin-polarized 39K-40K Bose-Fermi mixture realized in a single-chamber setup with an unenriched potassium dispenser as the source of atoms. We are able to magnetically confine more than 2.2 × 105 fermions (F = 9/2 , m F = 9/2) and 1.4 × 107 bosons (F = 2 , m F = 2) with a lifetime exceeding 1.2 s. For this work, we have developed a versatile laser tailored for sub-Doppler cooling of all naturally occurring potassium isotopes and their mixtures. This laser system incorporates innovative features, such as the capability to select an isotope by activating or deactivating specific acousto-optic modulators that control the light seeding tapered amplifiers. Switching between isotopes takes ∼1 µs without any mechanical adjustment of the components.

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Sub-Doppler laser cooling and magnetic trapping of natural-abundance fermionic potassium

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Magnetic trapping of an ultracold $^{39}$ K- $^{40}$ K mixture with a versatile potassium laser systemMagnetic trapping of an ultracold $^{39}$K-$^{40}$K mixture with a versatile potassium laser system

Mateusz Bocheński, Jakub Dobosz, Mariusz Semczuk

We present a dual isotope magneto-optical trap (MOT), simultaneous sub-Doppler laser cooling, and magnetic trapping of a spin-polarized $^{39}$ K- $^{40}$ K Bose-Fermi mixture realized in a single-chamber setup with an unenriched potassium dispenser as the source of atoms. We are able to magnetically confine more than $2.2\times10^5$ fermions ( $F=9/2\,m_F=9/2$ ) and $1.4\times10^7$ bosons ( $F=2\,m_F=2$ ) with a lifetime exceeding 1.2 s. For this work, we have developed a versatile laser tailored for sub-Doppler cooling of all naturally occurring potassium isotopes and their mixtures. This laser system incorporates innovative features, such as the capability to select an isotope by activating or deactivating specific acousto-optic modulators that control the light seeding tapered amplifiers. Switching between isotopes takes $\sim$1 $\mathrmμ$ s without any mechanical adjustment of the components. As a final step in characterizing the laser system, we demonstrate sub-Doppler cooling of $^{41}$ K.We present a dual isotope magneto-optical trap (MOT), simultaneous sub-Doppler laser cooling, and magnetic trapping of a spin-polarized $^{39}$K-$^{40}$K Bose-Fermi mixture realized in a single-chamber setup with an unenriched potassium dispenser as the source of atoms. We are able to magnetically confine more than $2.2\times10^5$ fermions ($F=9/2\,m_F=9/2$) and $1.4\times10^7$ bosons ($F=2\,m_F=2$) with a lifetime exceeding 1.2 s. For this work, we have developed a versatile laser tailored for sub-Doppler cooling of all naturally occurring potassium isotopes and their mixtures. This laser system incorporates innovative features, such as the capability to select an isotope by activating or deactivating specific acousto-optic modulators that control the light seeding tapered amplifiers. Switching between isotopes takes $\sim$1 $\mathrmμ$s without any mechanical adjustment of the components. As a final step in characterizing the laser system, we demonstrate sub-Doppler cooling of $^{41}$K.

arXiv:2404.19670Apr 30, 20240 citations

We report on an experimental realization of a two-dimensional magneto-optical trap (2D-MOT) that allows the generation of cold atomic beams of

^{39}\mathrm{K}

and

^{41}\mathrm{K}

bosonic potassium isotopes. The high measured fluxes up to $1.0\ifmmode\times\else\texttimes\fi{}{10}^{11}\phantom{\rule{0.3em}{0ex}}\mathrm{atoms}∕\mathrm{s}$ and low atomic velocities around

33\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}

are well suited for a fast and reliable three-dimensional magneto-optical trap loading, a basilar feature for new generation experiments on Bose-Einstein condensation of dilute atomic samples. We also present a simple multilevel theoretical model for the calculation of the light-induced force acting on an atom moving in a MOT. The model gives a good agreement between predicted and measured flux and velocity values for our 2D-MOT.

Magnetic trapping of an ultracold

^{39}

K-

^{40}

K mixture with a versatile potassium laser system

We present a dual isotope magneto-optical trap (MOT), simultaneous sub-Doppler laser cooling, and magnetic trapping of a spin-polarized

^{39}

K-

^{40}

K Bose-Fermi mixture realized in a single-chamber setup with an unenriched potassium dispenser as the source of atoms. We are able to magnetically confine more than

2.2\times10^5

fermions (

F=9/2\,m_F=9/2

) and

1.4\times10^7

bosons (

F=2\,m_F=2

) with a lifetime exceeding 1.2 s. For this work, we have developed a versatile laser tailored for sub-Doppler cooling of all naturally occurring potassium isotopes and their mixtures. This laser system incorporates innovative features, such as the capability to select an isotope by activating or deactivating specific acousto-optic modulators that control the light seeding tapered amplifiers. Switching between isotopes takes $\sim$1

\mathrmμ

s without any mechanical adjustment of the components. As a final step in characterizing the laser system, we demonstrate sub-Doppler cooling of

^{41}