23.06.2009icssur 2009 - thomas juffmann23.06.2009icssur 2009 - thomas juffmann matter wave...

23.06.2009ICSSUR 2009 - Thomas JuffmannSFB & START

23.06.2009ICSSUR 2009- Thomas Juffmann

Matter wave lithography of C60 molecules


Quantum or classical?

[1] Arndt et al., Nature 401, 6754, p.680 (1999). [2] Hackermuller et al. PRL 91, 9, 090408 (2003)Measuring molecular polarizibilities:[3] Berninger et al., Phys. Rev. A 76, 013607 (2007)Tests on decoherence:[4] Hornberger et al., PRL 90, 16, 160 401 (2003)[5] Hackermüller et al., Nature 427, 6976, p.711 (2004)

C60, 720 amu, [1] C44H30N4 , 614amu, [2] C62H36F93NOSi2, 2634 amu


Tools for molecular interferometry experiments

• Molecular beam source• Velocity selector• Interferometer• Detection scheme:

– Quadrupole mass spectrometer

– Surface based detection scheme


Talbot-Lau Interferometry

dd1 1 = d= d2 2 = 257nm= 257nm

LL1 1 = L= L2 2 = d²/= d²/λλ = 12,5mm = 12,5mm

λλ = 5,5pm = 5,5pm

G1G1 G2G2 G3G3

integralintegraldetectordetector

ovenoven

Countrate on the detectorCountrate on the detectorafter the 3. gratingafter the 3. grating

Interference Interference patternpattern

L1 L2


G1 G2 G3

S l it s o u r c e

a r r a y

S c a n n i n g

m a s k

D i ffr a c ti o n

G1 G2

S l it s o u r c e

a r r a y

S c r e e nD i ffr a c ti o n

Surface Detection and Nanopatterns


The detection surface: Si(111) 7x7

• Large-scale atomically flat surfaces obtainable• 19 dangling bonds per unit cell (Takayanagi et al., J. VAC. SCI.

TECHNOL. A 3, 3, p.1502 (1985)) • Used for the calibration of the STM


STM: C60 on Si(111) 7x7

• Molecules immobilized at room temperature (Chen et al., Phys. Rev. B 49, 11, 7612 (1994).)

• UHV conditions


Surface Detection and Nanopatterns

• Particle and wave nature in a single image

• High detection efficiency• Scalable to larger objects (1.5µm)²

(1.5µm)²


Conclusion and Outlook

• New surface based detection scheme for molecular interferometry:Sensitivity & Scalability!

• New method for noncontact lithography of molecules:– Each molecule is a

functional element– Unbalanced interferometer

=> pattern has a smaller period than the mask

C174H24F18O24, 5916amu,synthesized by Prof. Mayor, Basel


The „Quantum lithography crew“

Markus Arndt Hendrik Ulbricht Andras Major Sarayut Deachapunya

Stefan Truppe Philipp Geyer Thomas Juffmann


Magnifying or demagnifying interferometers

• d3/d1 = 1/(r-s*d2/d1); r > s > 0

• L1/L2 = r*d1/(s*d2)-1

• Magnification only for different grating periods• Demagnification results in decreased visibility

• http://arxiv.org/abs/0804.3006v1


The molecular beam source


Gravitational velocity selection

• y(t)=-g*t²/2+vy0*t+y0

• vz>>vy => t=z/vz

• Longer scanning times• More information• UHV compatible


The helical velocity selector

• High transmission for narrow velocity selection

• Good visibility all over the sample

• Hard to apply in UHV environment

• Short lifetime => rotating discs?


Detection of Interferograms

• Scanning tunneling microscopy (STM):– High resolution– Post-processing– UHV system and atomically flat surfaces required

• Fluorescence microscopy:– Easy to apply– Very selective– Evaluation in one picture– In Situ and in real time?


STM: Tip preparation

• Tips made of tungsten• Electrochemically etched

in a 5% KOH solution• Drop off => Etching stops

suddenly• Heated to remove oxide

layer• Atomic resolution is

reliably obtained


Fluorescence microscopy: In situ and in real time?

Sensitivity?

single molecules

Immobilization?

Variety of Fluorophores and Surfaces

Diffraction Limit?• Magnifying interferometer• Increased position accuracy by

analyzing the point spread function

(1.5nm!, Yildiz et al., Science, 300 (2003), 2061.)


FIONA (fluorescence imaging with one nanometer accuracy)

• Position accuracy dependent on SNR; down to 1nm!• Only a few molecules within diffraction limited region (=>

bleaching, PALM, STORM….)• Yildiz et al., Science, 300 (2003), 2061.• Kural et al., J.Phys.: Condens. Matter, 17 (2005), 3979.


Best visibility so far: 16% at 2160 amu

Quantum „dogs“ and „elephants“C62H36F93NOSi2 (2634 amu), comparable in mass to insulin A

50000 50200 50400 50600 50800 51000

140

160

180

200

220

240

260

280

Co

un

ts /

3s

3rd Grating Postion

2 views of the same molecule @ 600 K


The velocity selection

• Visibility is velocity dependent!

• g = 254nm => van der Waals interaction

• For high visibility: small openings=> low transmission, narrow peak


Advantages of gas phase deposition

16.05.2007Breakfast Talk - Thomas Juffmann

• Add a deflector: - Electric beam writing - Sort the molecules by their

polarizabilities

• No masks directly on the surface

• No pollution from solution

• Molecular holograms


STED (stimulated emission depletion microscopy)

• Detected light stems from a small region of interest

• Westphal et al., Phys.Rev.Lett., 94 (2005), p.143903.

• Hell et al., Applied Physics B, 60 (1995), 495.

• Hell, Science 316 (2007), 1153. .


TIRFM (total internal reflection microscopy)

• Evanescent wave excites only molecules that are very close to the surface

• No excitation light reaches objective

• 10^(-6) Monolayers of TPP visible• Moerner et al., Rev.Sci.Instr., 74

(2003),8.


Fluoreszenz in situ and in real time?

• Detection of single molecules:– Confocal microscopy– TIRFM

• Resolution limited due to diffraction:– Magnifying interferometer– Increase Position Accuracy (1.5nm!, Yildiz et al., Science,

300 (2003), 2061.)



Molecular switches

• Fluorated azobenzene:

- vaporizable - good visibility > 80%

- mass: 1034 a.u.

• Change in shape, size and properties

- Switchable on surfaces?

- Thermal relaxation?cistrans



Molecules as single photon sources?

• Review: W E Moerner, New J. Phys. 6 (2004) 88

• Best Result: Lounis et al. 2000 Nature 407, 491

Terrylene, quantum yield ~1

P-terphenyl

Confocal fluorescence image (10x10 um²)

Works at room temperature!Successful anti-bunching:

• cw-Laser • pulsed Laser => single photon on demand

• Excitation lifetime : t = 4 ns• p(1) ~ 0.85; • p(2) < 8*10-4



Optical properties of C60 towers

x (nm

)

z (nm)

y (nm)

Deposition: Zeilinger group, Vienna UniversityAFM : Jo Krenn, G raz University

• C60 on oxidized silicon• Electronic properties?

• Nanostructured template for the binding of larger molecules?



How do the molecules get there?

• Source/– laser ablation– thermal beams

• Lithography:– Molecular interferometry– Contact printing

23.06.2009icssur 2009 - thomas juffmann23.06.2009icssur 2009 - thomas juffmann matter wave...

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