Research perspectives

IAPP: COLDBEAMS 7th October, 2013, Paris

Andy McCulloch

European Research Council: ERC-StG- COLDNANO

Marie Curie Industry-Academia Partnerships and Pathways: FP7-PEOPLE-2009-IAPP

Orsay Physics

• Matthieu Viteau• Bernard Rasser• Pierre Sudraud

Laboratoire Aimé Cotton

• Yoann Bruneau• Guyve Khalili

• Andy McCulloch• Isam Manai

• Mehdi Hamamda• Hans Lignier• Pierre Pillet

• Daniel Comparat

• Justine Houplin• Roger Azria

• Lionel Amiaud• Anne Lafosse

Institut des sciences molécullaires d’Orsay

Controlled Chemistry:Nanofunctionalisation of surface molecules

• The ability to control and orientate chemical reactivity in the condensed phase

• Many applications, particularly in biotechnology and biosensing

• Electrons drive bond cleavage, creating highly reactive molecules

• Local interaction(s) lead to the synthesis of new molecules or bonding with the surface

Tuning E(e-) for successive Dissociative Electron Attachement

• Current source: 5 µA on (1 mm²) (1 A/m²) with 1 eV resolution

• New source: 10 pA on (10 µm)² (105 A/m²) with 1 meV resolution

Controlled Chemistry

Gold

Terminal group

spac

er

Aro

mat

icA

lkyl

1eV6eV Deposited molecular film

9eV

Controlled chemistry

• After surface modification, the surface is analysed using HREELS

• Low current source + serial detection = Long acquisition times (hours)

• Energy range: 0-2eV, few meV resolution

Can we help, not only with functionalisation, but additionallyHREELS?

6eV beam

0-2 eV beam with meV resolution

Functionalisation/HREELS

First steps

• Produce electrons!

• Measure beam properties: emittance, etc.

Energy spread

• Need to know the energy spread– Spectrometer

Can we perform other experiments simultaneously?

Deterministic single ion source

• Huge demand for sources of single ions– Large number of applications: Quantum

computation, ion implantation, etc.

• Rydberg atoms provide a simple solution for deterministic source.

The idea• Use fs laser to excite a small volume of

atoms (<10 um)• Blockade limits excited atom number

Feedback system

• Use the electron position to actively correct the ion trajectory (ultimate aberration correction)

• Only possible to correct ions

Position sensitivedetector (DLD)

Feedback controlsystem

Ultimate source characterisation

• Would like to what is the coldest possible electron/ion temperature

• Accurate electron temperature measurement is difficult, gives little insight into heating mechanism(s) c.f origin of 10 K

• Ideally, want high resolution images of both electron k and x

• Electron microscope

• Photoemission electron microscope

Measurement of x/k

The PEEM

• PEEM provides high resolution (real space) imaging and (transverse) momentum imaging.

• Combined with TOF spectroscopy– Access to the longitudinal components

Can directly measure k and x

TOF PEEM

• Using a (3D) MOT as the sample, photoionisation dynamics can be investigated

Simulations

• With existing setup, we should be able to obtain high resolution images• Upfield emission directly resolvable!

Experiment planned Early 2014

LAC outlook• Short term:

– Source diagnostics– Single ion source

• Mid-term– TOF PEEM: Electron source characterisation– Nanofunctionalisation

• Long-term– Electron/ion feedback– HREELS

Outlook: other elements?• Cold atom electron/ion sources show a

lot of promise

• Cooling molecules can provide additional elements: e.g. CN, BaF …

CN for implanting diamond

No sources of: B, C, N, O, F, Si, Ga, Ge, As

Questions? Comments?

Thoughts?

Laser cooling = collimation Rydberg = excitation + Field ionisation

Improvefocus limit (10µm)x(∆E/E)

Huge domain of applications and improvement for: Spectrometers, irradiation, induced chemistry Imaging Sputtering, deposition

- +

IONIZATION OF COLD ATOMS or MOLECULESTo create Bright Ion/Electron beams

Example: Implantation of N atoms from Cooling of CN molecules