Download - Arndt matter wave interferometry
Matter wave interferometrywith complex molecules
Markus ArndtQuantum optics, Quantum nanophysics &
Quantum information, University of Vienna
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 ?
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
Can we extend double slit interferometry to larger things ?
What is philosophically debateable in this animation ?
How to test the quantum wave nature of clusters & molecules?1. Multi‐slit far‐field diffraction
C Sourc e60
Col limati on
5 µm 5 µm
1.3 3 m1.13 m
G ratin gVeloc itySelec tor Ioniz ation L aser
C Ofen60 5 µm5 µm
1 331.33 m1.13 m
S lt D t ktLGeschwindigkeitsselektor GitterSpalte DetektorLaserse e to Gitter
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:
Longitudinal coherence requirements: Velocity selection
2-slitλt d h d i ftowardsscreen
g Θ
n-th order interference: path length differenceand coherence length of n λ
λ
and coherence length of n λ⋅
1 0
1,2
1,4
rate
v- distribution:
( )−3 2 2m0f(v) ~ v exp (v v ) / v
0 4
0,6
0,8
1,0
lized
coun
tr
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
norm
a
after selection (b):
Δv / v ~ 0.6
p. 7
0 100 200 300 400 500 600velocity (m/s)
( )Δv / v ~ 0.16
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
Reminder: How to test the quantum wave nature of clusters & molecules?
3000
4000
C60sin θ n λ/g ' 20μradC Sourc e60
Col limati on
5 µm 5 µm
1.3 3 m1.13 m
G ratin gVeloc itySelec tor Ioniz ation L aser ol
ecul
es
2000
3000sin θ = n · λ/g ' 20μrad
400dete
cted
mo
10002nd order inteference requirescoherence length
300
num
bero
fd
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 radii2 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 resemblesthe other!
Observing single molecules in scanning tunneling microscopy in Vienna
p. 10See poster by Stefan Truppe, Thomas Juffmann, Philipp Geyer
Observing single fullerenes on Si 111 (7x7)
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
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
2d
t(x)⇒ ψL
= ≡λ
⋅ ⋅ ⋅ ⋅TalbotL 2 m 2d L mSelf imaging if L= multiple of the Talbot‐Length:
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
2pLTalbot =
First realization of Talbot Lau interferometry for molecules
Def. Visibility:
max min
i
I IVI I
−=
+
Def. Visibility:
max minI I+
IImax
Imin
g = 990 nm (period)
d = 450 nm (slit opening)
b = 500 nm (membrane thicknes)
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. Gratinggf = 1/5 f = 1/2 f = 2/3
At our opening ratio d/g=f = 0.48: classical contrast nearly vanishing
Proving the wave nature of large moleculesin the presence of VdW forces …
50Quantum with Van der WaalsQuantum without grating potential
Quantum with Casimir-Polder
40
g g pClassical with van der WaalsClassical without grating potential
30
bilit
y [%
]
20visi
24018014012010790800
10
24018014012010790 80 v [m/s]
Phys. Rev. Lett. 88, 100404 (2002).
Avoid van der Waals: Far‐field diffraction of C60 at an optical phase grating
800 experim enttheory ohne Laser
400
y
P 5 5 W
n 1
50 s
200
400 P=5.5 W
cou
nts
in
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)
A new type of interferometerA new type of interferometer
Kapitza‐Dirac‐Talbot‐LauKapitza Dirac Talbot Lau
Interferometerf
An interferometer without van der Waals dephasing Kapitza‐Dirac‐Talbot‐Lau Interferometer
Advantage:
g=266 nm
16 x higher masses underconditions similar toconditions similar toprevious TLI
Generally scalable to muchhigher masses (1.000.000 u…)
Kapitza‐Dirac Talbot‐Lau Interferometer
1st Grating 2nd G ti 3rd G ti1st GratingCoherence preparation
2nd GratingDiffraction
3rd GratingDetection Mask
2pLλpLTalbot =
Precision requirementsGratings by Tim Savas, Massachusetts Institute of Technology & nm2
Photo‐lithographical manufacturing
Supportstructure: 1.5µm
Period: 266.38nm
Required accuracy : Δg < 0.5 Å < H‐atom !!
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
Quantum interferometry with „polyatomic strings“perfluoralkyl‐functionalized diazobenzenes
700
600
650
500
550
600
Cou
nts
400
450
500
50,0 50,2 50,4 50,6 50,8 51,0 51,2400
Position of 3rd grating (µm)
Gerlich et al., Nature Physics 3, 711 (2007) Interference in very good agreement
with quantum expectations!
High‐contrast quantum interference has been observed in Vienna with ….
Fullerene C60& C7060 70
Fluoro‐Fullerene C60F36 & C60F48
Porphyrins & derivatives
Perfluoroalkyl‐functionalized molecules
Towards higher mass & complexity
1. Chemical approach
p. 26
Slow beams of very large moleculesA molecular "octupus"
Eur. Phys. J. D 46, 307 (2008).
Perfluoralkylated Buckyball
C60[(CF2)11CF3]1060[( 2)11 3]10
8 fluoro‐carbon chains6910m = 6910 amu
N = 430 atoms
Very low thermal velocity
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
Towards higher mass & complexity
2. Cluster approach
p. 29
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
Neutral biomolecular clusters & metal complexes
n
CaTrp10CaTrp10
Cluster formation up to Trp30 is triggeredCluster formation up to Trp30 is triggeredby the presence of a single Calcium ion
M. Marksteiner, P. Haslinger, et al...
J. Am. Soc. Mass. Spectrom. 19, 1021 (2008)
Similarly : other neutral biocluster‐metal complexes with up tom>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
New perspectives for supermassive interferometry
Towards interfereometry with m= 1,000,000 u ...
Cryogenically cold metal clustersCryogenically cold metal clusters
Laser ionization gratings
Compact setupi d fcm‐sized even for
MDa –particles ?
Reiger, Hackermüller, Arndt
Opt. Comm. 264, 326‐332 (2006).
M l l M t lMolecule Metrology1. Static polarizability1. Static polarizability
2. Optical polarizability
3 Susceptibilities and structure analysis3. Susceptibilities and structure analysis
p. 34
Interferometric deflectometry:Nanoimprint on the molecular beam ⇒ high resolution for forces !
Laser gratingQuadrupole mass detector
( t 9000 )
Mechanicalgrating
(up to 9000 amu)
Source
grating
Mechanicaligrating
The laser interacts through optical polarizability
p. 35
The static field gradient (homogeneous force field) interacts throughstatic polarizability & permanent electric dipole moment
1. Interferometric deflectometry for static polarizabilities
Phys. Rev. A. 76, 013607 (2007).
ZählrateZählrate
ecto
rde
fle8
VerschiebungVerschiebung
10 12.5
15
7.5
55678
µm]
(E )Eα ∇r r r
02.5
15
17.520
HV1234
shift
[
d 2
(E )Exm vα ∇
∝r
HV –Power Supply [kV]
5 10 15voltage [kV]00
120
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 ųα(C70) / α(C60) = 1.24 ± 0.06
p. 37Phys. Rev. A. 76, 013607 (2007)
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 ?
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).
Proposed interferometric sorting of polypeptidesY = 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 UniversityAnal. Chem. 75, 5512 (2003)
Proposed interferometric sorting of polypeptides (2)
Talbot‐Lau deflectometry can selectivelytransmit one peptide sequence and block YWG = redtransmit one peptide sequence and block another one. YGW = blue
Quantum simulations show better contrastthan classical fringes !than classical fringes !
p. 41Gas phase sorting of nanoparticlesNanotechnology 19, 045502 (2008).
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
Summary: Molecular Quantum Optics
p. 43
The 2008 team in Molecular Quantum Optics
Stefan Gerlich
HendrikUlbricht
Markus Marksteiner
Stefan Nimmrichter
Tarik Berrada
MicheleSclafani
Philipp Haslinger
Michael Gring
Thomas Juffmann
StefanTruppe
Philipp Geyer
Peter Asenbaum
International collaborations on these projectsProf. Marcel Mayor, Univ. Basel
Coworkers 2005‐2007Mag. 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
Thank youThank you
for your attention!yLiterature:
Markus Arndt, Klaus Hornberger, and Anton ZeilingerP bi h li i f h ldProbing the limits of the quantum worldPhysics 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)