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Arndt matter wave interferometry
- 1. Matter wave interferometry with complex molecules Markus Arndt Quantum optics, Quantum nanophysics & Quantum information, University of Vienna
- 2. The 2 Sides of Quantum Interferometry with large Molecules Quantum physics is a universally valid theory Are there any mass, size or complexity limits ? Quantum physics is a precise theory Can we use quantum interferometry for molecule metrology ?
- 3. Bohr‐Einstein Dialogue: Can complementarity be tricked ? Path–information in particle‘s recoil on the upper slit ! Will interference still be seen ? NO ! Because of the Δx/Δp uncertainty relation p. 3
- 4. Can we extend double slit interferometry to larger things ? What is philosophically debateable in this animation ?
- 5. How to test the quantum wave nature of clusters & molecules? 1. Multi‐slit far‐field diffraction C Sourc e60 Col limati on 5 µm 5µm 1.3 3m1.13 m G ratin gVeloc ity Selec tor Ioniz ationL aser C Ofen60 5 µm5 µm 1 331.33 m1.13 m S lt D t ktL Geschwindigkeits selektor GitterSpalte DetektorLaser se e to Gitter
- 6. What are the basic coherence requirements ? Spectral (= longitudinal) coherence: Different wavelengthsDifferent wavelengths ⇒ different diffraction angles ⇒ averaging over minima and maxima Coherence length: Coherence requirement for n‐th order interference:
- 7. Longitudinal coherence requirements: Velocity selection 2-slit λ t d h d i ftowards screen g Θ n-th order interference: path length difference and coherence length of n λ λ and coherence length of n λ⋅ 1 0 1,2 1,4 rate v- distribution: ( )−3 2 2 m0f(v) ~ v exp (v v ) / v 0 4 0,6 0,8 1,0 lizedcountr a )b ) typical width (a): ( )m0f(v) v exp (v v ) / v Δv / v ~ 0 6 0 100 200 300 400 500 600 0,0 0,2 0,4 norma after selection (b): Δv / v ~ 0.6 p. 7 0 100 200 300 400 500 600 velocity (m/s) ( ) Δv / v ~ 0.16
- 8. What are the other basic coherence requirements ? Spatial (= transverse) coherence: Different emitter locations ⇒ transverse shift of interference patterns ⇒ averaging over minima and maxima Can be avoided if Far‐field diffraction: Divergence angle Θ div << diffraction angle Θ diff Talbot Lau interferometry: Transverse interferometry prepared by the setup
- 9. Reminder: How to test the quantum wave nature of clusters & molecules? 3000 4000 C60 sin θ n λ/g ' 20μrad C Sourc e60 Col limati on 5 µm 5µm 1.3 3m1.13 m G ratin gVeloc ity Selec tor Ioniz ationL aser olecules 2000 3000 sin θ = n · λ/g ' 20μrad 400 detectedmo 10002nd order inteference requires coherence length 300 numberofd 2nd order interference is an indication for van der Waals forces ! 200 n Molecule interference is a single‐ particle phenomenon: -150 -100 -50 0 50 100 150 100 particle phenomenon: 1. Average distance 100 µm = 10000 van der Waals radii 2 All molecules are in thermal Nature 401, 680 (1999). Am. J. Phys. 71, 319 (2003). 150 100 50 0 50 100 150 Detector position (µm) 2. All molecules are in thermal mixture. No molecule resembles the other!
- 10. Observing single molecules in scanning tunneling microscopy in Vienna p. 10 See poster by Stefan Truppe, Thomas Juffmann, Philipp Geyer
- 12. Towards higher mass and complexity:p y Near field interferometry can cope with high masses small diffraction angleshigh masses, small diffraction angles & dilute moleculear beams
- 13. Mathematical background to the Talbot‐Effect: Self‐imaging without a lens Fresnel diffraction at a grating of transmission function t(x) (Summation over Huygens spherical wavelets) dGrating is a periodic structure: Fourier expansion L Insertion into ψ yields: t(x)=⇒ ψL 2 d t(x)⇒ ψL = ≡ λ ⋅ ⋅ ⋅ ⋅TalbotL 2 m 2 d L mSelf imaging if L= multiple of the Talbot‐Length:
- 14. Extension of near‐field interferometry to spatially incoherent sources: Talbot‐Lau Interferometry 1. grating: 2. grating: 3. grating: prepares coherence diffraction scanning mask incoherent molecular beam 2 λ 2 p LTalbot =
- 15. First realization of Talbot Lau interferometry for molecules Def. Visibility: max min i I I V I I − = + Def. Visibility: max minI I+ IImax Imin g = 990 nm (period) d = 450 nm (slit opening) b = 500 nm (membrane thicknes)
- 16. Distinguish Quantum interference from Moiré shadow fringes V = 0 % V = 20 %V = 100 %Intensity V = 0 % V = 20 %V = 100 %Intensity Screen 2. Grating 1. Gratingg f = 1/5 f = 1/2 f = 2/3 At our opening ratio d/g=f = 0.48: classical contrast nearly vanishing
- 17. Proving the wave nature of large molecules in the presence of VdW forces … 50 Quantum with Van der Waals Quantum without grating potential Quantum with Casimir-Polder 40 g g p Classical with van der Waals Classical without grating potential 30 bility[%] 20 visi 2401801401201079080 0 10 2401801401201079080 v [m/s] Phys. Rev. Lett. 88, 100404 (2002).
- 18. Avoid van der Waals: Far‐field diffraction of C60 at an optical phase grating 800 experiment theory ohne Laser 400 y P 5 5 W n150s 200 400 P=5.5 W countsin 150 300 P=7.5 W 200 50 P=9.5 W -65 -43 -22 0 22 43 65 0 100 detector position x [µm]D k i i ( ) Phys. Rev. Lett. 87, 160401 (2001) detector position x [µm]Detektorposition (µm)
- 19. A new type of interferometerA new type of interferometer Kapitza‐Dirac‐Talbot‐LauKapitza Dirac Talbot Lau Interferometerf
- 20. An interferometer without van der Waals dephasing Kapitza‐Dirac‐Talbot‐Lau Interferometer Advantage: g=266 nm 16 x higher masses under conditions similar toconditions similar to previous TLI Generally scalable to much higher masses (1.000.000 u…)
- 21. Kapitza‐Dirac Talbot‐Lau Interferometer 1st Grating 2nd G ti 3rd G ti1st Grating Coherence preparation 2nd Grating Diffraction 3rd Grating Detection Mask 2 p L λ p LTalbot =
- 22. Precision requirements Gratings by Tim Savas, Massachusetts Institute of Technology & nm2 Photo‐lithographical manufacturing Support structure: 1.5µm Period: 266.38nm Required accuracy : Δg < 0.5 Å < H‐atom !!
- 23. Alignment conditions for the KDTLI : needed to avoid geometrical dephasing Roll (each grating ) ΔΘ < 500 µrad Pitch (each grating ) Δθ < 1 mrad Yaw (each grating ) Δφ < 200 µradYaw (each grating ) Δφ < 200 µrad Relative grating positioning ΔL / L < 10- 4 Grating mismatch 0.05 nm Laser waist Δw0 ~ 5 µm Laser beam pointing ΔΘdi < 1mradLaser beam pointing ΔΘdiv< 1mrad non-stationary accelerations Δa < 0.001 g
- 24. Quantum interferometry with „polyatomic strings“ perfluoralkyl‐functionalized diazobenzenes 700 600 650 500 550 600 Counts 400 450 500 50,0 50,2 50,4 50,6 50,8 51,0 51,2 400 Position of 3rd grating (µm) Gerlich et al., Nature Physics 3, 711 (2007) Interference in very good agreement with quantum expectations!
- 25. High‐contrast quantum interference has been observed in Vienna with …. Fullerene C60 & C7060 70 Fluoro‐Fullerene C60F36 & C60F48 Porphyrins & derivatives Perfluoroalkyl‐functionalized molecules
- 26. Towards higher mass & complexity 1. Chemical approach p. 26
- 27. Slow beams of very large molecules A molecular "octupus" Eur. Phys. J. D 46, 307 (2008). Perfluoralkylated Buckyball C60[(CF2)11CF3]1060[( 2)11 3]10 8 fluoro‐carbon chains 6910m = 6910 amu N = 430 atoms Very low thermal velocity
- 28. Overcoming the "ionization limit for organic molecules": Dye‐tagged perfluoroalkyl‐functionalized dendrimers … I ti bIn preparation by our ESF MIME partners in Basel Prof. Marcel Mayor & coworkers
- 29. Towards higher mass & complexity 2. Cluster approach p. 29
- 30. Cluster sources for biomolecules: Laser desoprtion into cold mixing channel Source: version 1 • Straight channel • 266 nm ionization Source: version 2 • U‐shaped channel • UV (157 nm) ionization• UV (157 nm) ionization • Admixture of CaCO3 ⇒ large cIusters detected!g
- 31. Neutral biomolecular clusters & metal complexes n CaTrp10CaTrp10 Cluster formation up to Trp30 is triggeredCluster formation up to Trp30 is triggered by the presence of a single Calcium ion M. Marksteiner, P. Haslinger, et al... J. Am. Soc. Mass. Spectrom. 19, 1021 (2008)
- 32. Similarly : other neutral biocluster‐metal complexes with up to m>6000 amu (Gramidin D)n ‐ clusters with n=1..5 Tryptophan‐Gramicidin clusters Trp Clusters seeded with Ba, Sr, Cu, Na, … Nucleotide‐cluster (Guanine)n with n=1..50Nucleotide cluster (Guanine)n with n 1..50 Pure Polypeptide‐Cluster (Trp‐Trp‐Gly)n with n=1..5 1. There is an entire zoo of clusters we still need to understand 2 Interferometry will be a valuable tool as soon as we are able to2. Interferometry will be a valuable tool as soon as we are able to a. Slow these clusters b Cool also their internal degrees of freedomb. Cool also their internal degrees of freedom
- 33. New perspectives for supermassive interferometry Towards interfereometry with m= 1,000,000 u ... Cryogenically cold metal clustersCryogenically cold metal clusters Laser ionization gratings Compact setup i d fcm‐sized even for MDa –particles ? Reiger, Hackermüller, Arndt Opt. Comm. 264, 326‐332 (2006).
- 34. M l l M t lMolecule Metrology 1. Static polarizability1. Static polarizability 2. Optical polarizability 3 Susceptibilities and structure analysis3. Susceptibilities and structure analysis p. 34
- 35. Interferometric deflectometry: Nanoimprint on the molecular beam ⇒ high resolution for forces ! Laser grating Quadrupole mass detector ( t 9000 ) Mechanical grating (up to 9000 amu) Source grating Mechanical igrating The laser interacts through optical polarizability p. 35 The static field gradient (homogeneous force field) interacts through static polarizability & permanent electric dipole moment
- 36. 1. Interferometric deflectometry for static polarizabilities Phys. Rev. A. 76, 013607 (2007). ZählrateZählrate ectordefle 8 VerschiebungVerschiebung 10 12.5 15 7.5 55 6 7 8 µm] (E )Eα ∇ r r r 0 2.5 15 17.5 20 HV1 2 3 4 shift[ d 2 (E )E x m v α ∇ ∝ r HV – Power Supply [kV] 5 10 15 voltage [kV] 0 0 1 20
- 37. Static polarizabilities: More precise values for C60 shiftshift ∂∂ UU²²/v/v²²∂∂ UU²²/v/v²² α(C60) = 86.2 ± 3.5 ± 3.5 ų Relative Polarizability: α(C70) = 106.6 ± 2.7 ± 4.3 ų α(C70) / α(C60) = 1.24 ± 0.06 p. 37Phys. Rev. A. 76, 013607 (2007)
- 38. Quantum interference of the fluorinated catalyst: C96H48Cl2F102P2Pd (3378 amu) Detection using EI‐QMS on the fragment m = 1597 amu Where does the l l d ?moelcule decay? In the source or p. 38 in the detector ?
- 39. The power dependence of the fringe visibility gives the answer ! G Cl i l thGreen: Classical theory Red: Quantum theory intact molecule Blue: Quantum theory 1600 amu fragmentBlue: Quantum theory 1600 amu fragment p. 39Angew. Chem. Int. Ed. 47, 6195 (2008).
- 40. Proposed interferometric sorting of polypeptides Y = Tyrosine Polypeptides = chains of amin acids Diff diff l i ibili iDifferent sequences ⇒ different electric susceptibilities G = Glycine W = Tryptophan p. 40 LSIM, Lyon & INRA Montpellier & Indiana University Anal. Chem. 75, 5512 (2003)
- 41. Proposed interferometric sorting of polypeptides (2) Talbot‐Lau deflectometry can selectively transmit one peptide sequence and block YWG = redtransmit one peptide sequence and block another one. YGW = blue Quantum simulations show better contrast than classical fringes !than classical fringes ! p. 41 Gas phase sorting of nanoparticles Nanotechnology 19, 045502 (2008).
- 42. Proposed: Absolute cross section measurements using single photon recoil Absorption of a single photon is sufficient tophoton is sufficient to create a clearly discernible side‐peak Relative height of the peaks measure the cross‐ sectionsection Advantage: Absolute values Ever for absorption lengths > 10.000 km
- 44. The 2008 team in Molecular Quantum Optics Stefan Gerlich Hendrik Ulbricht Markus Marksteiner Stefan Nimmrichter Tarik Berrada Michele Sclafani Philipp Haslinger Michael Gring Thomas Juffmann Stefan Truppe Philipp Geyer Peter Asenbaum International collaborations on these projects Prof. Marcel Mayor, Univ. Basel Coworkers 2005‐2007 Mag. Martin Berninger ⇒ Univ. Innsbruck Dr. Klaus Hornberger, LMU Munich Prof. H. Gleiter, FZ Karlsruhe Prof. Helmut Ritsch, Univ. Innsbruck Dr. Sarayut Deachapunya, ⇒ Burapha Univ. Dr. Fabienne Goldfarb ⇒ LAC, Orsay Dr. Lucia Hackermüller ⇒ Mainz / Wien Dr. Tim Savas, MIT Cambridge Dr. Nikos Doltsinis, King‘s College, London Prof. Christoph Dellago, Univ. Wien Mag. Gregor Kiesewetter ⇒ Univ. Bremen Dr. Elisabeth Reiger ⇒ Regensburg Dr. Alexander Stibor ⇒ Univ. Tübingen
- 45. Thank youThank you for your attention!y Literature: Markus Arndt, Klaus Hornberger, and Anton Zeilinger P bi h li i f h ldProbing the limits of the quantum world Physics World 18, 35 ‐40 (2005). M. Arndt & K. Hornberger in a chapter on Molecule interference in the book “Proceedings of the international school of physics “Enrico Fermi”book Proceedings of the international school of physics Enrico Fermi , Course CLXXI ‐ "Quantum Coherence in Solid State Systems", Ed P. Schwendimann, Societa Italiana di Fisica (2008). Atom interferometry:Atom interferometry: Rev. Mod. Phys. Cronin, Schmiedmayer, Pritchard (2008)