Inelastic collisions of ultracold polar LiCs molecules with caesium atoms in an optical dipole trap

Abstract

We investigate collisions of ultracold polar LiCs molecules and ultracold caesium atoms. LiCs molecules are formed in an optical dipole trap by photoassociation of caesium and lithium atoms via the B(1)Π excited state followed by spontaneous emission to the X(1)Σ(+) ground state and the lowest triplet state a(3)Σ(+). The molecules are then stored together with caesium atoms in the same optical trap. Rate coefficients for the loss of molecules induced by collisions with surrounding Cs atoms are measured for molecular ensembles produced via different photoassociation resonances. The results are analyzed in terms of the unitarity limit for the inelastic rates and predictions from the universal model of Idziaszek and Julienne (Phys. Rev. Lett., 2010, 104, 113202).

Quantum Theory of Reactive Collisions for1/rnPotentials

“…We present explicit analytical formulas as well as numerical studies for the van der Waals (n = 6) and polarization (n = 4) potentials. Our model agrees well with recent merged beam experiments on Penning ionization, spanning collision energies from 10mK to 30K [Henson et Much recent work involves the inelastic and reactive collisions of cold atoms or molecules with one another [1][2][3][4] or with ions in hybrid traps [5][6][7]. These could involve the ultracold regime with translational temperature on the order of µK or less or the cold regime between a few mK and a few K. Systematic theoretical principles for understanding the quantum dynamics of such collisions are needed.…”

“…Cx, 03.65.Nk, 34.10.+x, 34.50.Lf Much recent work involves the inelastic and reactive collisions of cold atoms or molecules with one another [1][2][3][4] or with ions in hybrid traps [5][6][7]. These could involve the ultracold regime with translational temperature on the order of µK or less or the cold regime between a few mK and a few K. Systematic theoretical principles for understanding the quantum dynamics of such collisions are needed.…”

Quantum-defect model of a reactive collision at finite temperature

“…It also recently became possible to produce ultracold KRb molecules in optical traps by using Feshbach resonance and the STIRAP technique, high phase space density [9][10][11]. A number of different experiments basing on this technique is now being performed with other species, for now mainly consisting of alkali atoms [12][13][14][15]. The electronic, hyperfine, rotational and vibrational state of the produced molecules can be controlled with external fields, so the dependence of chemical reaction rates on the internal state can be analyzed experimentally.…”

Theory of Long-Range Ultracold Atom-Molecule Photoassociation

“…Many experiments demonstrated that conditions suitable for inducing chemical reactions between ultracold ground state alkali-metal atoms and molecules tightly bound in their electronic ground state are reachable. Ultracold collisions between Cs atoms and Cs 2 [5,6] or LiCs [7] molecules, of Rb and Cs atoms with RbCs molecules [8], or of K and Rb atoms with KRb molecules [9] have been detected through atom trap losses. Three-body recombination in a Rb quantum gas has been characterized [10], and features associated to universal N -body (up to N = 5) resonances induced by collisions between atoms and weaklybound molecules have been observed in quantum degenerate gases [11][12][13][14][15][16].…”