Maykel L. González-Martínez

1. A New Method for Efficient Calculations On Sympathetic Cooling Maykel L. González-Martínez http://www.dur.ac.uk/m.l.gonzalez-martinez Jan 31, 2013. MMQA'13, London

2. MMQA: Main goal MicroKelvin Molecules in a Quantum Array Create polar molecules with sufficiently high density¹ & low enough temperature² to form interacting quantum arrays ¹ ⩾ 10⁷ molecules/trap volume ~ 1010 molecules/cm3 ² ⩽ 10⁻⁶ K Dec. 16, 2010. Imperial College, London.

3. TRAP DYNAMICS Lifetimes in traps Trap losses Sympathetic cooling THERMALIZATION Buffer-gas cooling Evaporative cooling Collisions Reproduce,Understand, Predict Jan 31, 2013. MMQA'13, London

4. 'Traditional' coupled-channel methodology Problem N coupled (differential) equations effort (time) ∝N3 Observables! (S/T matrix) interpretation Jan 31, 2013. MMQA'13, London

5. DS Jin and Y Je; Phys. Today 27 (2011)‏ Frustration 1 Basis size Jan 31, 2013. MMQA'13, London

6. Hmm... if we really need to make it 'real'... Potential 'survey' + field strength '2' + angle f1/f2 ... Well... and potentials are not 100% accurate Collisions take place in traps... ... at a given 'temperature'. Field strength Collision energy 2 Parameters Jan 31, 2013. MMQA'13, London

7. Jan 31, 2013. MMQA'13, London

8. To 'CC' or not to 'CC'... ... sure there are other ways, aren't there? James' (et al.) Multichannel Quantum Defect Theory Phys. Rev. A84, 042703 (2011) Phys. Rev. A86, 022711 (2012) arXiv:1212.5290 (2012) George (Optimisations, approximations) Maykel (Approximate hyperfine) 2 1 1 I know... but how far can we go 'if'...? Tsherbul's (et al.) total-J approximation J. Chem. Phys.133, 184104 (2010) Phys. Rev. A84, 040701 (2011) J. Chem. Phys.137, 024103 (2012) Phys. Rev. A85, 052710 (2012) 1 Uff... do we really have to? '1' Bohn's (et al.) statistical approach: No (if it's difficult!) Phys. Rev. A85, 062712 (2012) Jan 31, 2013. MMQA'13, London

9. 'Small' R Etot≫ E∞ Fully coupled effort ∝N3 'Large' R Etot≈ E∞ Fully uncoupled effort ∝N Just once! ... a few times? As many as you want! Rmin Rmatch Rmax Y Full CC + MQDT parameters = S/T Jan 31, 2013. MMQA'13, London

10. Test case 1 (low anisotropy) Mg(1S) + NH(3S-) in magnetic fields Jan 31, 2013. MMQA'13, London

11. Mg(1S) + NH(3S-).Y(E) (fixed B). MQDT: JFE Croft et al.; Phys. Rev. A84, 042703 (2011)‏ Jan 31, 2013. MMQA'13, London

12. Mg(1S) + NH(3S-).Y(B) (fixed E). MQDT: JFE Croft et al.; Phys. Rev. A84, 042703 (2011)‏ Jan 31, 2013. MMQA'13, London

13. Mg(1S) + NH(3S-). Feshbach resonances. MQDT: JFE Croft; PhD Thesis (2012)‏ Jan 31, 2013. MMQA'13, London

14. Test case 2 (large anisotropy + long-range spin-spin) Li(2S) + NH(3S-) in magnetic fields Jan 31, 2013. MMQA'13, London

15. Li(2S) + NH(3S-). CC vs MQDT (204 vs 5). CC: AOG Wallis et al.; Eur. Phys. J. D65, 151 (2011)‏ MQDT: JFE Croft and JM Hutson;arXiv:1212.5290 (2012)‏ Jan 31, 2013. MMQA'13, London

16. Li(2S) + NH(3S-). MQDT(converged basis 1,800 vs900). MQDT: JFE Croft and JM Hutson;arXiv:1212.5290 (2012)‏ Jan 31, 2013. MMQA'13, London

17. Summary • “Coupled-channels” have taken us this far... • MQDT provides the best(?) solution to the “parameters” problem (and we've optimized it!) • ... a solution to the “basis size” problem is needed Jan 31, 2013. MMQA'13, London

18. Many Thanks!