We present a way of evaporative cooling using microwave-induced transitions in a crossed-beam optical dipole trap. By combining the optical and magnetic forces with gravity it allows to spatially select the most energetic atoms and drive them out of the trap by microwave. After 480 ms of evaporation, our data show the phase space density of the Cs atoms increases by a factor of 3.2 and the temperature is reduced from 2.4 µK to 400 nK. The cooling efficiency is mainly limited by the trap heating. This method provides another way to cool neutral atoms in optical trap and reach temperatures in the nano-Kevin regime.We present a way of evaporative cooling using microwave-induced transitions in a crossed-beam optical dipole trap. By combining the optical and magnetic forces with gravity it allows to spatially select the most energetic atoms and drive them out of the trap by microwave. After 480 ms of evaporation, our data show the phase space density of the Cs atoms increases by a factor of 3.2 and the temperature is reduced from 2.4 µK to 400 nK. The cooling efficiency is mainly limited by the trap heating. This method provides another way to cool neutral atoms in optical trap and reach temperatures in the nano-Kevin regime.

Journal of the Physical Society of JapanFeb 13, 20070 citations

Simulations of evaporation to deep Fermi degeneracy in microwave-shielded molecules

Reuben R. W. Wang, Shrestha Biswas, Sebastian Eppelt +3 more

In the quest toward realizing novel quantum matter in ultracold molecular gases, we perform a numerical study of evaporative cooling in ultracold gases of microwave-shielded polar fermionic molecules. Our Monte Carlo simulations incorporate accurate two-body elastic and inelastic scattering cross sections, realistic modeling of the optical dipole trap, and the influence of Pauli blocking at low temperatures. The simulations are benchmarked against data from evaporation studies performed with ultracold NaK molecules, showing excellent agreement. We further explore the prospects for optimizing the evaporation efficiency by varying the ramp rate and duration of the evaporation trajectory. Our simulation shows that it is possible to reach $<10%$ of the Fermi temperature under optimal conditions even in the presence of two-body molecular losses.In the quest toward realizing novel quantum matter in ultracold molecular gases, we perform a numerical study of evaporative cooling in ultracold gases of microwave-shielded polar fermionic molecules. Our Monte Carlo simulations incorporate accurate two-body elastic and inelastic scattering cross sections, realistic modeling of the optical dipole trap, and the influence of Pauli blocking at low temperatures. The simulations are benchmarked against data from evaporation studies performed with ultracold NaK molecules, showing excellent agreement. We further explore the prospects for optimizing the evaporation efficiency by varying the ramp rate and duration of the evaporation trajectory. Our simulation shows that it is possible to reach $<10%$ of the Fermi temperature under optimal conditions even in the presence of two-body molecular losses.

arXiv:2407.14466Physical Review AOct 10, 20245 citations

Collisions between linear polar molecules trapped in a microwave field

Masatoshi Kajita, А. V. Avdeenkov

The European Physical Journal DNov 14, 20067 citations

Microwave traps for cold polar molecules

David P. DeMille, David R. Glenn, Jalean Joyanne Petricka

arXiv:physics/0407038The European Physical Journal DNov 1, 2004103 citations

All-optical runaway evaporation to Bose-Einstein condensation

Jean‐François Clément, Jean-Philippe Brantut, Martin Robert-De-Saint-Vincent +4 more

We demonstrate runaway evaporative cooling directly with a tightly confining optical-dipole trap and achieve fast production of condensates of $1.5\ifmmode\times\else\texttimes\fi{}{10}^{5}$ $^{87}\text{R}\text{b}$ atoms. Our scheme uses a misaligned crossed-beam far off-resonance optical-dipole trap (MACRO-FORT). It is characterized by independent control of the trap confinement and depth allowing forced all-optical evaporation in the runaway regime. Although our configuration is particularly well suited to the case of $^{87}\text{R}\text{b}$ atoms in a 1565 nm optical trap, where an efficient initial loading is possible, our scheme is general and will allow all-optical evaporative cooling at constant stiffness for every optically trappable atomic or even molecular species.We demonstrate runaway evaporative cooling directly with a tightly confining optical-dipole trap and achieve fast production of condensates of $1.5\ifmmode\times\else\texttimes\fi{}{10}^{5}$ $^{87}\text{R}\text{b}$ atoms. Our scheme uses a misaligned crossed-beam far off-resonance optical-dipole trap (MACRO-FORT). It is characterized by independent control of the trap confinement and depth allowing forced all-optical evaporation in the runaway regime. Although our configuration is particularly well suited to the case of $^{87}\text{R}\text{b}$ atoms in a 1565 nm optical trap, where an efficient initial loading is possible, our scheme is general and will allow all-optical evaporative cooling at constant stiffness for every optically trappable atomic or even molecular species.

arXiv:0903.2745Physical Review AJun 19, 2009109 citations

<10%

of the Fermi temperature under optimal conditions even in the presence of two-body molecular losses.

We demonstrate runaway evaporative cooling directly with a tightly confining optical-dipole trap and achieve fast production of condensates of $1.5\ifmmode\times\else\texttimes\fi{}{10}^{5}$

^{87}\text{R}\text{b}

atoms. Our scheme uses a misaligned crossed-beam far off-resonance optical-dipole trap (MACRO-FORT). It is characterized by independent control of the trap confinement and depth allowing forced all-optical evaporation in the runaway regime. Although our configuration is particularly well suited to the case of

^{87}\text{R}\text{b}

atoms in a 1565 nm optical trap, where an efficient initial loading is possible, our scheme is general and will allow all-optical evaporative cooling at constant stiffness for every optically trappable atomic or even molecular species.