Scattering of ultracold molecules in the highly resonant regime

Compared to purely atomic collisions, ultracold molecular collisions potentially support a much larger number of Fano-Feshbach resonances due to the enormous number of rovibrational states available. In fact, for alkali-metal dimers we find that the resulting density of resonances cannot be resolved at all, even on the sub-μK temperature scale of ultracold experiments. As a result, all observables become averaged over many resonances and can effectively be described by simpler, nonresonant scattering calculations. Two particular examples are discussed: nonchemically reactive RbCs and chemically reactive KRb. In the former case, the formation of a long-lived collision complex may lead to the ejection of molecules from a trap. In the latter case, chemical reactions broaden the resonances so much that they become unobservable.

[1]  D. Nesbitt.  Toward state-to-state dynamics in ultracold collisions: lessons from high-resolution spectroscopy of weakly bound molecular complexes. , 2012, Chemical reviews.

[2]  M. Mayle,et al.  Statistical Aspects of Ultracold Resonant Scattering , 2012, 1203.6868.

[3]  S. Kotochigova,et al.  Universalities in ultracold reactions of alkali-metal polar molecules , 2011, 1108.3866.

[4]  P. Julienne,et al.  Universal ultracold collision rates for polar molecules of two alkali-metal atoms. , 2011, Physical chemistry chemical physics : PCCP.

[5]  R. Ferber,et al.  Singlet and triplet potentials of the ground-state atom pair Rb + Cs studied by Fourier-transform spectroscopy , 2011 .

[6]  D. S. Jin,et al.  Controlling the quantum stereodynamics of ultracold bimolecular reactions , 2010, 1010.3731.

[7]  J. Bohn,et al.  Dynamics of ultracold molecules in confined geometry and electric field , 2010, 1010.3245.

[8]  R. Grimm,et al.  Hyperfine, rotational, and vibrational structure of the a 3 Σ u + state of Rb 87 2 , 2010, 1009.2075.

[9]  D. Akamatsu,et al.  Coherent transfer of photoassociated molecules into the rovibrational ground state. , 2010, Physical review letters.

[10]  P. Julienne,et al.  Simple quantum model of ultracold polar molecule collisions , 2010, 1007.2652.

[11]  P. Zoller,et al.  Universal rates for reactive ultracold polar molecules in reduced dimensions. , 2010, Physical review letters.

[12]  E. Meyer,et al.  Product-state control of bi-alkali-metal chemical reactions , 2010, 1004.3317.

[13]  J. Bohn,et al.  Electric field suppression of ultracold confined chemical reactions , 2010, 1003.4026.

[14]  S. Kotochigova.  Dispersion interactions and reactive collisions of ultracold polar molecules , 2010, 1003.2672.

[15]  J. Bohn,et al.  Strong dependence of ultracold chemical rates on electric dipole moments , 2010, 1001.5062.

[16]  J. Ye,et al.  Dipolar collisions of polar molecules in the quantum regime , 2010, Nature.

[17]  G. Mitchell,et al.  Random matrices and chaos in nuclear physics: Nuclear reactions , 2010, 1001.2422.

[18]  D. S. Jin,et al.  Quantum-State Controlled Chemical Reactions of Ultracold Potassium-Rubidium Molecules , 2009, Science.

[19]  P. Julienne,et al.  Universal rate constants for reactive collisions of ultracold molecules. , 2009, Physical review letters.

[20]  D. Chemistry,et al.  An ultracold high-density sample of rovibronic ground-state molecules in an optical lattice , 2009, 0909.4700.

[21]  Cheng Chin,et al.  Feshbach resonances in ultracold gases , 2008, 0812.1496.

[22]  R. Krems,et al.  Magnetic field modification of ultracold molecule–molecule collisions , 2008, 0808.3592.

[23]  J. Ye,et al.  A High Phase-Space-Density Gas of Polar Molecules , 2008, Science.

[24]  R. Krems,et al.  Formation of slow molecules in chemical reactions in crossed molecular beams , 2008 .

[25]  P. Żuchowski,et al.  Hyperfine energy levels of alkali-metal dimers: Ground-state polar molecules in electric and magnetic fields , 2008, 0807.1907.

[26]  S. Falke,et al.  Potassium ground-state scattering parameters and Born-Oppenheimer potentials from molecular spectroscopy , 2008, 0804.2949.

[27]  P. Zoller,et al.  Strongly correlated 2D quantum phases with cold polar molecules: controlling the shape of the interaction potential. , 2006, Physical review letters.

[28]  R. Levine.  Molecular Reaction Dynamics: Frontmatter , 2005 .

[29]  Gus Hancock,et al.  Molecular reaction dynamics , 2003 .

[30]  C. Greene,et al.  Multichannel Cold Collisions: Simple Dependences on Energy and Magnetic Field , 1998 .

[31]  A. R. P. Rau,et al.  Atomic Collisions and Spectra , 1986 .

[32]  F. Smith,et al.  Lifetime Matrix in Collision Theory , 1960 .

[33]  Eugene P. Wigner,et al.  Lower Limit for the Energy Derivative of the Scattering Phase Shift , 1955 .