Physics and Chemistry with Diatomic Molecules Near Absolute Zero. Tanya Zelevinsky & ZLab Columbia University, New York

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1 Physics and Chemistry with Diatomic Molecules Near Absolute Zero Tanya Zelevinsky & ZLab Columbia University, New York

2 Pupin Columbia E. Fermi I. I. Rabi

3 10 What is Ultracold? MK kk K 1 0 mk mk laser cooling of atoms

4 Beyond Cold Atoms Indirect molecule cooling optical or magnetic Direct molecule cooling buffer gas (sympathetic) cooling

5 Why Cold Molecules? atomic H spectrum molecular H 2 spectrum New science Quantum-state-controlled ultracold chemistry Dipolar quantum gases & many-body physics Enhancement of EDMs and parity violation New physics and 5 th force Fundamental constants & variations

6 Ultracold Diatomic Molecules Indirect molecule cooling Sr Sr Sr Sr

7 Tight Trapping: Optical Lattice Clocks l/2 standing wave of light create Sr 2 molecules 10-6 K optical probe trapping potential: ac Stark shift quantized motional states

8 Molecular Lattice Clock 88 Sr G. Reinaudi et al., PRL 109, (2012)

9 Science with Cold and Ultracold Molecules Ultracold chemistry Molecular clocks Table-top particle physics

10 Ultracold Chemistry Quantum-state selected reactants and products Bimolecular collisions AB + AB A 2 + B 2 Photoassociation A + A + g A * 2 Photodissociation A 2 + g A + A *

11 Ultracold Chemistry Quantum-state selected reactants and products Complete quantum state control of reverse collision Photodissociation A 2 + g A + A *

12 Ultracold Chemistry Quantum-state selected reactants and products Photodissociation Sr 2 + g Sr + Sr * The hydrogen atom of ultracold chemistry Experiment first-principles theory comparison

13 Ultracold Photodissociation Photofragment angular distribution V J = 2 J = 0 (J = 4; M = 1) Matter-wave interference dependence!

14 Photofragment Angular Distributions i = 1 i = M. McDonald et al., Nature 535, 122 (2016)

15 Photofragment Angular Distributions i = 1 i = 0 Y e iδ Y M. McDonald et al., Nature 535, 122 (2016)

16 Probing Reaction Barriers = 1 1 S + 3 P 1 = 0

17 PD light Probing Reaction Barriers Continuum (J = 1) 1 S + 3 P 1

18 M. McDonald et al., Nature 535, 122 (2016) Probing Reaction Barriers MHz MHz MHz b 20 J = 2 J = 0 I θ 1 + β 2 P 2 cos θ Continuum energy (MHz)

19 M. McDonald et al., Nature 535, 122 (2016) Probing Reaction Barriers MHz MHz MHz b 20 J = 2 J = 0 I θ 1 + β 2 P 2 cos θ barrier QC theory Continuum energy (MHz)

20 Field Control of Photodissociation Comparable energies at ~ 1 mk: Kinetic Barrier Zeeman

21 Field Control of Photodissociation Comparable energies at ~ 1 mk: Kinetic Barrier Zeeman M. McDonald et al., PRL, accepted

22 Field Control of Photodissociation B Sr 2 + g Sr + Sr * E PD Energy = 30 MHz = 1.5 mk Key point: Mixing of partial waves in the continuum M. McDonald et al., PRL, accepted

23 Science with Cold and Ultracold Molecules Ultracold chemistry Molecular clocks Table-top particle physics

24 Clocks Electronic Vibrational Coherence time of superposition Intrinsic Trap & environment

25 Two-Body Quantum Optics Identical nuclei Inversion symmetry superradiant S P + P S odd (u) subradiant X 2G 0 E1 0! S S even (g) S P P S even (g) M1 E2

26 Two-Body Quantum Optics Subradiance R 2 μ M1 μ E1 R λ 2 10 R = 100 a 0 Need 10 4 suppression of E1! Molecules B. Bussery-Honvault and R. Moszynski, Mol. Phys. 104, 2387 (2006)

27 W. Skomorowski et al., JCP 136, (2012) B. McGuyer et al., Nature Phys. 11, 32 (2015) Two-Body Subradiance R R

28 Subradiant Lifetime 5.5 ms molecule-light coherence time B. McGuyer et al., Nature Phys. 11, 32 (2015)

29 B. McGuyer et al., Nature Phys. 11, 32 (2015) Two-Body Subradiance Predissociation E R -4 R -2.5 Q > R 2

30 Trap-Insensitive Spectroscopy Magic optical lattice trap create molecules 10-6 K optical probe

31 Dynamic polarizability a Trap-Insensitive Spectroscopy Magic optical lattice trap 2 1 Lattice wavelength Coherent superposition of 1 + 2

32 M. McDonald et al., PRL 114, (2015) Trap-Insensitive Spectroscopy Magic -lattice optical absorption spectrum red sideband carrier blue sideband

33 M. McDonald et al., PRL 114, (2015) Trap-Insensitive Spectrosopy G T

34 Dynamic polarizability Dynamic polarizability Trap-Insensitive Spectroscopy Magic optical lattice trap narrow resonance >100 nm Lattice wavelength Nonresonant crossing: Traditional choice; hard to find Resonant crossing: Heating/loss Lattice wavelength Resonant crossing: * No heating/loss! * Easy to find

35 Clock Based on Molecular Vibrations 1 Σ <30 THz

36 Dynamic polarizability Trap-Insensitive Spectroscopy Magic optical lattice trap narrow resonance nm Lattice wavelength Resonant crossing: * No heating/loss! * Easy to find

37 Line width (MHz) Trap-Insensitive Spectroscopy Magic optical lattice trap nm 600 coherence time 160 Hz

38 Trap-Insensitive Spectroscopy Magic optical lattice trap 160 Hz vibrational clock resonance 26 THz Q = (fiber limited)

39 Science with Cold and Ultracold Molecules Ultracold chemistry Molecular clocks Table-top particle physics

40 New Mass-Dependent Forces V = GM2 r 1 + Ae r/λ Yukawa A < 10 1 nm! Need state-of-the-art measurement of van der Waals interatomic force J. J. Lutz and J. M. Hutson, JMS 330, 43 (2016) M. Borkowski et al., arxiv:

41 Molecular QED and 5 th force Born-Oppenheimer approximation E tot E el + E vib + E rot Beyond B-O adiabatic nonadiabatic relativistic finite-nuclear-size μ = m e Am μ 2 p α 2 μ, α 3 μ higher-order α 4 μ < 1 Hz r c /a Σ 84 Sr, 86 Sr, 88 Sr dimers (6 combinations): fit up to 5 m-dependent corrections

42 Y. N. Pokotilovski, Phys. At. Nucl. 69, 924 (2006) Y. Kamiya et al., PRL 114, (2015) M. Bordag et al., Phys. Rep. 353, 1 (2001) M. Borkowski et al., J. Phys. Conf. Ser. 810, (2017) Strength of non-1/r 2 interaction log A Molecular QED and 5 th Force Neutron scattering 2006 Neutron scattering 2015 Van der Waals forces: 1-Hz Sr 2 spectroscopy projection Casimir forces log (l / m)

43 Zlab Current support: Columbia University, NSF, ONR, AFOSR, Templeton Foundation, Heising-Simons Foundation Theory: Mickey McDonald: APS DAMOP Doctoral Thesis Prize 2017 Robert Moszynski Iwona Majewska U. of Warsaw Geoff Iwata Stan Kondov Paul P. Konrad Wenz Alex S. Rees McNally Chih-Hsi Lee Kon Leung T. Z.