Feshbach resonances, molecular bound states and prospects of ultracold molecule formation in mixtures of ultracold K and Cs

Abstract

We consider the possibilities for producing ultracold mixtures of K and Cs and forming KCs molecules by magnetoassociation. We carry out coupled-channel calculations of the interspecies scattering length for ${}^{39}$KCs, ${}^{41}$KCs and ${}^{40}$KCs and characterize Feshbach resonances due to s-wave and d-wave bound states, with widths ranging from below 1 nG to 5 G. We also calculate the corresponding bound-state energies as a function of magnetic field. We give a general discussion of the combinations of intraspecies and interspecies scattering lengths needed to form low-temperature atomic mixtures and condensates and identify promising strategies for cooling and molecule formation for all three isotopic combinations of K and Cs.

11 pages, 4 figures plus Supplemental Material

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Cited by in corpus (7)

• Observation of interspecies Feshbach resonances in an ultracold ${}^{39}$K-${}^{133}$Cs mixture and refinement of interaction potentials
• Observation and modelling of bound-free transitions to the $X^1{\Sigma }^{+}$ and $a^3{\Sigma }^{+}$ states of KCs
• The $a^3{\Sigma }^{+}$ state of KCs revisited: hyperfine structure analysis and potential refinement
• Study of excited electronic states of the ${}^{39}$KCs molecule correlated with the K($4^2$S)+Cs($5^2$D) asymptote: experiment and theory
• Intensities of KCs $E(4{)}^1{\Sigma }^{+}\to (a^3{\Sigma }^{+},X^1{\Sigma }^{+})$ band system up to dissociation threshold: an interplay between spin-orbit, hyperfine and rovibronic coupling effects
• Formation of ultracold ${}^{39}$K${}^{133}$Cs Feshbach molecules
• Enhancing quantum order with fermions by increasing species degeneracy