Post on 14-Dec-2015
www.tugraz.at
W I S S E N T E C H N I K L E I D E N S C H A F T
u www.tugraz.at
17. Januar 13
Name und OE, Eingabe über > Kopf- und Fußzeile
www.tugraz.at
Thursday, 2014-06-19Florian Lackner
3
Helium droplet assisted preparation of…
Molecules[1,2,3]
0.1 nm 1 nm 10 nm 100 nm
Clusters Nanowires
[1]…Science 273, 629-631 (1996)[2]…Phys. Rev. Lett. 100, 063001, (2008) [3]…J. Phys. Chem. A 117, 13719 (2013)
Volk et al. J. Phys. Chem. 138, 214312 (2013)
Thaler et al., submitted manuscript (2014)
www.tugraz.at
RbSr molecules
X2Σ+ ground state: electric and magnetic dipole moment
Thursday, 2014-06-19Florian Lackner
4
interesting for ultracold molecular physics[8]
RbSr has not been characterized experimentally…
… but extensively by theory because of increasing interest in RbSr [9,10,11,12,13]
[9]…Ẑuchowski et al. arXiv:1402.0702 (2014)[10]…Phys. Rev. Lett. 105, 153201 (2010)
[11]…Phys. Rev. A 88, 023601 (2013)[12]…Phys. Rev. A 82, 042508 (2010)[13]…Lackner et al. submitted manuscript (2014)
[8]…Phys. Rev. A 88, 023601 (2013)
www.tugraz.at
Production of RbSr Molecules on HeN
Thursday, 2014-06-19Florian Lackner
5
HeN
Pickup
Rb Sr
Source conditions: 15 K / 60 bard ~ 8 nm
www.tugraz.at
Spectroscopic Methods
Thursday, 2014-06-19Florian Lackner
6
Resonant two-photon ionization (R2PI) spectroscopy
Laser induced fluorescence (LIF) spectroscopy
Dispersed fluorescence (DF) spectroscopy
www.tugraz.at
Thursday, 2014-06-19Florian Lackner
7
RbSr on HeNTime-of-flight mass spectra
Monomers Dimers and RbSr
mass [amu]mass [amu]
ion
sig
na
l [a
rb.
u.]
ion
sig
na
l [a
rb.
u.]
Krois et al. in preparation
www.tugraz.at
RbSr Potential Energy CurvesMRCI calculations
Thursday, 2014-06-19Florian Lackner
8
For details see: talk FC07Friday 10:07 AMJohann Pototschnig
X2Σ+
RbSr-HeN:only X2Σ+ (ν" = 0) is populated (0.37 K)
Lackner et al. submitted manuscript (2014)
www.tugraz.at
RbSr-HeN Excitation SpectrumTheory vs. experiment
Thursday, 2014-06-19Florian Lackner
9
R2PI spectroscopy
Lackner et al. submitted manuscript (2014)
www.tugraz.at
42Σ+ state: Te = 14006(4) cm-1
ωe = 86(3) cm-1 ωexe = 1.2(0.7) cm-1
42Σ+←X2Σ+ Transition Vibrationally resolved
Thursday, 2014-06-19Florian Lackner
10
R2PI
LIF
Information onfree RbSr molecules
Insight intoRbSr-HeN
Krois et al. in preparation
www.tugraz.at
…desorb from the droplet upon laser excitation (42Σ+←X2Σ+ )
Thursday, 2014-06-19Florian Lackner
11
RbSr molecules…
Access to free RbSr molecules
www.tugraz.at
Dispersed Fluorescence SpectraFree 42Σ+ RbSr molecules
Thursday, 2014-06-19Florian Lackner
12
X2Σ+ ground state: ωe ~ 42 cm-1 Theory[9,10]: 38-42 cm-1
[9]…Ẑuchowski et al. arXiv:1402.0702 (2014)[10]…Lackner et al. submitted manuscript (2014)
www.tugraz.at
Thursday, 2014-06-19Florian Lackner
13
Dispersed Fluorescence SpectraFree RbSr molecules
relaxation
www.tugraz.at
Thursday, 2014-06-19Florian Lackner
14
Dispersed Fluorescence SpectraFree RbSr molecules
shifted by-90 cm-1
www.tugraz.at
What’s coming next ?
Thursday, 2014-06-19Florian Lackner
15
RbCa
Ca2
Helium droplet assisted “molecular engineering”
R2PI
LIF
www.tugraz.at
SummaryRecipe for the investigation of RbSr
Helium droplet assisted preparation of RbSr molecules
Covering large spectral ranges (11600 – 23000 cm-1) with R2PI spectroscopy
Preparing free RbSr molecules – DF spectroscopy
New perspectives for the formation of tailored molecules and ultracold molecular physics
Thursday, 2014-06-19Florian Lackner
16
www.tugraz.at
Thank you !
Thursday, 2014-06-19Florian Lackner
18
Günter Krois
Johann V. Pototschnig
Wolfgang E. Ernst
Thomas Buchsteiner
www.tugraz.at
Thursday, 2014-06-19Florian Lackner
19
LIF vs. R2PI and Fragmentation
www.tugraz.at
4²Σ+ Fit and Sr2 background correction
www.tugraz.at
Dispersed Fluorescence Spectroscopy – Sr2
www.tugraz.at
(3)2Π1/2,3/2←(1)2Σ+ Transition
SO splitting ~13.5 cm-1
resolved on the droplet!
Broadened, asymmetric peaks due to the simultaneous excitation of the molecule and vibrations of the droplet (phonons)
www.tugraz.at
Isotope-shift: (3)2Π1/2,3/2←(1)2Σ+ Transition
Isotope-shift
Free molecule[4]
8.2 cm-1
17.4 cm-1
28.2 cm-1
[4] Russon et al., J. Chem. Phys., 138, 194307 (2013)
9 cm-1
18 cm-1 31 cm-1
LiCa on HeN
www.tugraz.at
1