Suppression of Penning ionization in a spin-polarized mixture of rubidium and He<sup>*</sup>

Byron, Lesa; Dall, Robert; RuGway, Wu; Truscott, A. G.

doi:10.1088/1367-2630/12/1/013004

Cited by 19 publications

(28 citation statements)

References 18 publications

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“…The production of ultracold, heteronuclear, diatomic molecules in their ground state by coherently combining two di↵erent laser-cooled atomic species is currently an active research area [1][2][3][4] because of the potential for quantum information processing, [5][6][7][8][9][10][11] for cold chemistry, [12][13][14][15][16] the exploration of strongly interacting quantum systems [17][18][19][20] and precision measurement. [21][22][23][24] Heteronuclear molecules manifest an electric dipole moment when a direction is imposed by an electric field, 25 allowing study of long-range anisotropic interactions.…”

Section: Introductionmentioning

confidence: 99%

A versatile dual-species Zeeman slower for caesium and ytterbium

Hopkins

Butler

Guttridge

et al. 2016

Review of Scientific Instruments

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We describe the design, construction and operation of a versatile dual-species Zeeman slower for both Cs and Yb, which is easily adaptable for use with other alkali metals and alkaline earths. With the aid of analytic models and numerical simulation of decelerator action, we highlight several real-world problems affecting the performance of a slower and discuss effective solutions. To capture Yb into a magneto-optical trap (MOT), we use the broad $^1S_0$ to $^1P_1$ transition at 399 nm for the slower and the narrow $^1S_0$ to $^3P_1$ intercombination line at 556 nm for the MOT. The Cs MOT and slower both use the D2 line ($6^2S_{1/2}$ to $6^2P_{3/2}$) at 852 nm. We demonstrate that within a few seconds the Zeeman slower loads more than $10^9$ Yb atoms and $10^8$ Cs atoms into their respective MOTs. These are ideal starting numbers for further experiments on ultracold mixtures and molecules.Comment: 15 pages, 15 figures, 4 tables, revtex4-

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Section: Introductionmentioning

confidence: 99%

A versatile dual-species Zeeman slower for caesium and ytterbium

Hopkins

Butler

Guttridge

et al. 2016

Review of Scientific Instruments

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“…We do not observe atoms in the F = 2, m F = 1 state after evaporative cooling in the hybrid trap, which suggests that unwanted repopulation of this state during MW-evaporative cooling in the QMT does not take place, in contrast to harmonic magnetic traps. The next step is the application of the hybrid trap to an ultracold mixture of 87 Rb and metastable triplet 4 He [16], for which the spin purity of 87 Rb is of crucial importance, as detrimental interspecies Penning ionization is expected to be only sufficiently suppressed for a spin-polarized sample [15,16]. An experimental appealing feature of the hybrid trap is the moderate ODT powers that is needed, in our case 3.5 W. Here the usage of an ODT at a wavelength around 1550 nm, instead of a wavelength around 1064 nm, is solely motivated by metastable triplet 4 He, for which 1064 nm gives a blue-detuned ODT due to strong (laser cooling) transitions around 1083 nm (see e.g.…”

Section: Discussionmentioning

confidence: 99%

“…Our choice for the F = 2, m F = 2 state is primarily motivated by the suppression of inelastic collisions for an ultracold mixture of Rb and metastable triplet helium [15,16], similar to the case of other mixtures with Rb [17][18][19][20][21]. It also provides a stronger confinement than the F = 1, m F = −1 hyperfine substate, as in the QMT the peak density scales with the magnetic moment to the third power.…”

Section: Introductionmentioning

confidence: 99%

Efficient production of an 87Rb F = 2, mF = 2 Bose-Einstein condensate in a hybrid trap

et al. 2015

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Abstract. We have realized Bose-Einstein condensation (BEC) of87 Rb in the F = 2, mF = 2 hyperfine substate in a hybrid trap, consisting of a quadrupole magnetic field and a single optical dipole beam. The symmetry axis of the quadrupole magnetic trap coincides with the optical beam axis, which gives stronger axial confinement than previous hybrid traps. After loading 2 × 10 6 atoms at 14 μK from a quadrupole magnetic trap into the hybrid trap, we perform efficient forced evaporation and reach the onset of BEC at a temperature of 0.5 μK and with 4 × 10 5 atoms. We also obtain thermal clouds of 1 × 10 6 atoms below 1 μK in a pure single beam optical dipole trap, by ramping down the magnetic field gradient after evaporative cooling in the hybrid trap.

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“…To our knowledge, there exists only one investigation involving heteronuclear pairs of Rg* atoms, performed with metastable helium [17], and only two experiments involving one Rg* atom in combination with a ground state alkali-metal atom: Ar* and Rb [18] and He* and Rb [19]. It is the purpose of the present work to extend the available experimental data by the investigation of heteronuclear collision between all possible combinations of the stable isotopes of neon.…”

Section: Introductionmentioning

confidence: 97%

Heteronuclear collisions between laser-cooled metastable neon atoms

et al. 2012

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We investigate heteronuclear collisions in isotope mixtures of laser-cooled metastable ( 3 P2) neon. Experiments are performed with spin-polarized atoms in a magnetic trap for all two-isotope combinations of the stable neon isotopes 20 Ne, 21 Ne, and 22 Ne. We determine the rate coefficients for heteronuclear ionizing collisions to β21,20 = (3.9 ± 2.7) × 10 −11 cm 3 /s, β22,20 = (2.6 ± 0.7) × 10 −11 cm 3 /s, and β21,22 = (3.9 ± 1.9) × 10 −11 cm 3 /s. We also study heteronuclear elastic collision processes and give upper bounds for heteronuclear thermal relaxation cross sections. This work significantly extends the limited available experimental data on heteronuclear ionizing collisions for laser-cooled atoms involving one or more rare gas atoms in a metastable state. I. INTRODUCTIONDue to their high internal energy which surpasses the ionization energy of almost all neutral atomic and molecular collision partners, metastable rare-gas atoms (Rg*) prepared by laser cooling techniques [1] present a unique class of atoms for the investigation of cold and ultracold collisions [2]. With lifetimes ranging from 14.73 s (neon)[3] to 7870 s (helium) [4], the first excited metastable states present effective ground states for applying standard laser cooling techniques. The resulting extremely low kinetic energy of the laser-cooled atoms (≈ 10 −10 eV) stands in strong contrast to the high internal energy between 8 eV (xenon) and 20 eV (helium). This offers unique conditions not accessible with samples of lasercooled alkali-metal atoms. In particular, the high internal energy of the metastable state allows for Penning (PI) and associative (AI) ionizing collisions,to dominate losses in trapped Rg* samples at high densities. Since direct detection of the collision products (using electron multipliers) as well as of the remaining Rg* atoms is possible with high efficiency, detailed studies of homonuclear ionizing collisions have been carried out for all rare gas elements (see [1] for an overview). Additional motivation for these investigations arises from the fact, that favorable rate coefficients for inelastic but also for elastic collisions are essential for the achievement of quantum degeneracy which for Rg* atoms so far has only been demonstrated for 4 He [5-8] and 3 He [9]. For unpolarized Rg* samples, two-body loss rate coefficients for PI [10] between β = 6 × 10 −11 cm 3 /s for 132 Xe [11] and β = 1 × 10 −9 cm 3 /s for 22 Ne [12] have been measured. Spin polarizing the atoms to a spin-stretched * gerhard.birkl@physik.tu-darmstadt.de state may suppress PI: In a collision of atoms in spinstretched states the total spin of the reactants is larger than the total spin of the products. Thus, if spin is conserved, PI collisions should be significantly reduced. In the case of He* in the 3 S 1 state, a suppression of four orders of magnitude has been observed [7,13]. For the heavier rare gases, however, the metastable state 3 P 2 is formed by an exited s electron and a p 5 core with orbital momentum l = 1. This leads to an anisot...

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Suppression of Penning ionization in a spin-polarized mixture of rubidium and He^*

Cited by 19 publications

References 18 publications

A versatile dual-species Zeeman slower for caesium and ytterbium

A versatile dual-species Zeeman slower for caesium and ytterbium

Efficient production of an 87Rb F = 2, mF = 2 Bose-Einstein condensate in a hybrid trap

Heteronuclear collisions between laser-cooled metastable neon atoms

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Suppression of Penning ionization in a spin-polarized mixture of rubidium and He*

Cited by 19 publications

References 18 publications

A versatile dual-species Zeeman slower for caesium and ytterbium

A versatile dual-species Zeeman slower for caesium and ytterbium

Efficient production of an 87Rb F = 2, mF = 2 Bose-Einstein condensate in a hybrid trap

Heteronuclear collisions between laser-cooled metastable neon atoms

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Suppression of Penning ionization in a spin-polarized mixture of rubidium and He^*