The of the respond to intense

MVSem--Masterseminar
 2021-04-20

The of the :
Atoms&molecules
 respond to intense
 laser flashes
 Thomas Pfeifer
 MPIK Heidelberg

Fundamental Quantum Dynamics

 Interference of quantum states
 Feynman: "... the only mystery [at the heart of quantum mechanics]."
Potential

 position position
 Phase Phase

quantum dynamics
 a fundamental scientific question:
 “how do excited electrons move and interact
 in atoms and molecules?”

 spatial scale The
 R ~ sub/few Å “quantum
 few-body
 e- e-
 temporal scale problem”
 T ~ sub/few fs in strong fields

 Science goal:
 measure / understand / control
 the quantum dynamics of
 small systems Laser control of
(x-ray) movies of
single molecules
 in strong fields chemical reactions
 Petahertz-clocked x-ray precision
 computing spectroscopy

Electron Facts
• lightest charged elementary particle e-

• 'chemical glue', holding molecules together
 -> making and breaking of bonds in chemical reactions
• carriers of electric current
 -> electricity generation/conversion/transport
• carriers of information
 -> electronics, computing, data storage
• mediating interactions of matter with light
 -> role in photosynthesis, photovoltaics, vision, ...

 ...typically more than one electron involved...

What is the problem?
 (with two or more electrons)

 Correlated e- lectron dynamics
 e- e-
 interaction (Coulomb)
 Correlation
 symmetry (Fermions) Y( e- 1, e- 2) ≠ Ψ(e- 1) ×Ψ ( e- 2)
 'interacting' 'non-interacting'

 1
 location e- 2

 |Y( e- 1, e- 2)|2
problem for: 0
 - Hartree–Fock methods
 - DFT
 (exchange-correlation
 potential not known) location e- 1

Why is it important?
Time-dependent correlated e-lectron dynamics
 e- e-
 interaction (Coulomb)
 Correlation
 symmetry (Fermions) Y( e- 1, e- 2) ≠ Ψ(e- 1) ×Ψ ( e- 2)
 'interacting' 'non-interacting'

 any bonding orbital in matter
 Giant Magnetoresistance High Tc superconductivity
 typically occupied
 location e- 2

 by 2 electrons
 e-
 e-
 fundamental role in
 chemical reactions
 excitation transfer, e- transport
 energy conversion, radiation damage
 importance in
 location e- 1 many branches of science

the language electrons speak ...
 ... and why is it so fast?
Energy

 |ep
 ȁΨ2 ۧ
 |2p
 ȁΨ1 ۧ
 position x

 |1s

Wavepacket dynamics and observation
Energy

 Quantum beat period:
 ℏ
 ȁΨ2 ۧ ∆ = ≈ 4.1 fs / ∆ [eV]
 ∆ 
 − − 
 ȁΨ1 ۧ 1 2 
 Ψ ~Ψ1 ℏ + Ψ2 ℏ
 position x
 e.g. time-dependent position/dipole:
 = Ψ( ) ො Ψ( )
 − − − − 
 1 
 = Ψ1 ℏ 1 + Ψ2 ℏ 2 ො Ψ1 ℏ 1 + Ψ2 ℏ 2
 2
 ( 1 − 2 )
 = Ψ1 ො Ψ2 ) cos ℏ
 + 0 ( )

the language electrons talk ...
 ... and why is it so fast?
 Quantum beat period:
 ℏ
 ∆ = ≈ 4.1 fs / ∆ [eV]
 ∆ 
 |ep
 Oscillation period:

 |2p
 Hydrogen: Hydrogen:
 T = 0.4 fs (10-18 s) hn=10.2 eV
and the way Iron (H-like): Iron (Z=26, H-like):
 T = 0.6 as (10-18 s) hn= 6.9 keV
we "listen"...: Uranium (H-like): Uranium (Z=92, H-like):
 T = 48.0 zs (10-21 s) hn=86.3 keV
 |1s
Spectroscopy

The light sources: Provided by two parallel revolutions
 in ultrashort x-ray/XUV laser science

 F E
 ree lectron L
 asers and H H igh armonic G
 eneration

 SACLA
 specifications
 @Japan demonstrated thus far:

 ~1 Å lowest wavelength ~1 nm
FLASH
@Germany
 ~5 mJ largest pulse energy ~1 J

 ~0.5 fs shortest pulse duration ~50 as
 LCLS partially fully
 @USA
 coherent coherent

Quantum dynamics imaging and spectroscopy
 Our “Eyes” … and “Ears” …
 time delay
 small (!) g
 t quantum system
 photon spectra

 g

 I+
 I++ e- e- energy
 A-B+ g
 ions photon images

 Δ momentum
 electrons
momentum

 momentum

 atom picture from: http://startswithabang.com/?p=1795

Our Experimental Focus
 Employing

(F Eree lectron )L asers and
 Bright H H igh armonic G eneration
 Light
 to understand
 &control
 Atoms, Ions & Molecules
 "listening" "imaging"
Multidim. optical spectroscopy Reaction microscope/COLTRIMS

 Goal: extract
 time&energy-resolved complete coincidence
 detection of photons information detection of electrons/ions
 atom image from: http://startswithabang.com/?p=1795

Our Experimental Focus

(F Eree lectron )L
 asers and
 Bright H H igh armonic G eneration
 Light
 to understand
 &control
 Atoms, Ions & Molecules
 "listening" "imaging"
Multidim. optical spectroscopy Reaction microscope/COLTRIMS

 Goal: extract
 time&energy-resolved complete coincidence
 detection of photons information detection of electrons/ions

Experimental observation of few-body dynamics
Multidim. optical spectroscopy Reaction microscope/COLTRIMS

 Goal: extract
 time&energy-resolved complete coincidence
 detection of photons information detection of electrons/ions
Energy

 Energy
 dynamics of bound states dynamics of continuum states

 e- e-
 measure
 e- e- photons

 bound-bound bound-free
 transitions transitions
 Position Position

Strong-field Recollision Physics
 in “nonsequential” double ionization
N. Camus et al. Phys. Rev. Lett. 108, 073003
 high intensity low intensity
 Ar ?200 asec
 large recollision energy low recollision energy

 e- are the electrons
 field ionized
 e -
 at the same time e-
 e-
 e- e-
 e- a
 or with e-

 characteristic time delay

 ?

Experimental observation of few-body dynamics
Multidim. optical spectroscopy Reaction microscope/COLTRIMS

 Goal: extract
 time&energy-resolved complete coincidence
 detection of photons information detection of electrons/ions
Energy

 Energy
 dynamics of bound states dynamics of continuum states

 e- e-
 measure
 e- e- photons

 bound-bound bound-free
 transitions transitions
 Position Position

traditional spectroscopy
 (Kirchhoff, Bunsen, et al. @Heidelberg 1860)

Electrons in atoms already
taught us a lot of
fundamental physics! g

 g

 e.g. Fraunhofer et al.

 Phase Phase

 atom image from: http://startswithabang.com/?p=1795
 bunsen burner image from: http://www.west-michigan-family.com/holiday-archives-march.html
 flame image from: http://commons.wikimedia.org/wiki/File:Bunsen_burner_flame_types_.jpg

time-dependent absorption spectroscopy

 time delay
 gas-phase
 t isolated atoms
 Time-dependent
 absorption spectrum

 t

 near-VIS XUV XUV photon energy
femtosecond attosecond
 pulse pulse
 Phase Phase

Listening to phases
 Mozart Mozart Mozart
spectral intensity

 amplitude amplitude amplitude

 Frequency [Hz] Frequency [Hz] Frequency [Hz]
 spectral phase by spectral phase spectral phase
 by W. A. Mozart (1787) by Chance by Metallica (1992)
 (Eine kleine Nachtmusik) (randomized) (Nothing else matters)
 Metallica Metallica
 amplitude amplitude

 Frequency [Hz] Frequency [Hz]

Properties of different light sources

spectral spectral
 phase phase
 solar spectrum cw laser spectrum fs pulse laser spectrum

Bild-Quellen: http://www.bhakti-love.com/fotos/sonnenlicht.jpg,
http://climate.met.psu.edu/www_prod/data/frost/images/rainbow.jpg

time-dependent absorption spectroscopy
 What's the dynamics of bound states and resonances
 in short and strong fields?
 time delay
 t Time-dependent
 absorption spectrum

 t

 near-VIS XUV XUV photon energy
femtosecond attosecond
 pulse pulse
 Phase Phase

General: coupling of states
 coupling of one to coupling of one to coupling of one to a
 one other state multiple states continuum of states

 Quite well understood for cases of
 time-independent (or adiabatic) couplings
 1.5 1.5

 Energy E
 Energy E

 1.0
 What happens when the coupling is ultrashort ? 1.0

 0.5
 0.5 0.0 0.1 0.2
 0.0 0.1 0.2
 Coupling Strength  Coupling Strength 
 B
 Rabi oscillation Breit-Rabi U. Fano (1935)
 Phys. Rev. 124, 1866 (1961)
 in strong coupling e.g. Paschen-Back regime
 Nuovo Cim. 12, 154 (1935)
 1 Ω12 Ω13 Ω14 Ω( )
 1 Ω12 Ω21 2 Ω23 Ω24
 Ω21 2 Ω31 Ω32 3 Ω34 Ω( ) 
spectral intensity

 Ω41 Ω42 Ω43 4

 photon energy hn photon energy hn photon energy hn

fundamental e-–e- correlation in atoms
 prototypical target: He atom
|cont.,2e- |es,ep

 excitation
|cont.,1e- |2s,ep by XUV/soft-x-ray e-

 ...
 |3 |2s3p+|2p3s e-
 |2 |2p2p
 |1 |2s2p

 |1s,ep
 single-photon discrete states coupled to continuum
 double excitation by configuration interaction e-

 e- e-
 |0 |1s1s |2s2p
 |1s2 e-

doubly excited helium: Fano resonance

 ( + )2
 σ ~
|cont.,2e- |es,ep 1 + 2
 = Ugo Fano
 Phys. Rev.
|cont.,1e- |2s,ep 1 d ( sp2,n + ) 124, 1866
 VCI* d (1s, e p) (1961)

 ...
 Nuovo
 |3 |2s3p+|2p3s Cimento
 12, 154
 |2 |2p2p (1935)

 |1 |2s2p

 |1s,ep
 single-photon coupled
 double excitation by configuration interaction e-
 e- e-
 |0 |1s2 |2s2p
 |1s2 e-

doubly-excited helium, in a strong laser field

 ( + )2
 σ ~
 |cont.,2e- |es,ep 1 + 2
 “coupling”- pulse = Ugo Fano
 Phys. Rev.
 |cont.,1e- “control”-
 |2s,ep (VIS) 1 d ( sp2,n + ) 124, 1866
 VCI* d (1s, e p) (1961)

 ...
 Nuovo
 |3 |2s3p+|2p3s Cimento
 12, 154
 |2 |2p2p (1935)

 |1 |2s2p

 |1s,ep
attosecond coupled
 single-photon
 pulse by configuration interaction
 double excitation e-
 60-70 eV
 e- e-
 |0 |1s2 |2s2p
 |1s2 e-

doubly-excited helium, in a strong laser field

 |cont.,2e- |es,ep
 Previous work
 “coupling”- pulse (on laser coupling of
 |cont.,1e- “control”- (VIS) doubly-excited helium):

 ...
 Theory: e.g. Phys. Rev. A 24, 379 (1981)
 - Madsen, Themelis, Lambropoulos
 |3 |2s3p+|2p3s
 - Zhao, Chu, Lin et al.
 |2 |2p2p ... e.g. Phys. Rev. A 87, 013415 (2013)

 |1 |2s2p Experiment: Chem. Phys. 350, 7 (2008)
 |1s,ep - Loh, Greene, Leone, et al.
attosecond - Gilbertson, Chang et al.
 single-photon
 pulse ... Phys. Rev. Lett. 105, 263003 (2010
 double excitation
 60 eV
 Experimental challenge:
 |0 |1s1s - high (asec) temporal and
 - high (meV)
 required at the same time

Experimental setup
 for XUV absorption spectroscopy
 Fano resonances q= U. Fano
 Phys. Rev.
 of autoionizing states 1 d ( sp2,n+ )
 124, 1866
 VCI* d (1s, e p)
 (1961)
 Photon energy [eV]
 58 60 62 64 66
 1.5
 XUV

 Optical density [OD]
 2s2p
 Absorption
 light
 Spectrum [OD]
 1.0
 plane
 mirror sp2,3+
 0.5
 sp2,n+(4,5,6,7)
 toroidal
 focusing mirror
 0.0
 target gas cell:
 Helium .
 Variable Line Spacing
Experimental key challenge: High resolution (VLS) grating
In photon energy ... : DE = 20 meV (@60 eV) flat-field spectrometer

Experimental setup
 for time-resolved XUV absorption spectroscopy
 neon cell
 for high-harmonic Photon energy [eV]
 generation 58 60 62 64 66
 1.5

 Optical density [OD]
 XUV 2s2p
 Absorption
 pulse Spectrum [OD]
 1.0
 VIS
 split
 pulse
 mirror sp2,3+
 0.5
 sp2,n+(4,5,6,7)
 toroidal
 focusing mirror
 0.0
 target gas cell:
 Helium .
 Variable Line Spacing
Experimental key challenge: High resolution (VLS) grating
In photon energy ... : DE = 20 meV (@60 eV) flat-field spectrometer
... and time delay : Dt = 10 as

Experimental Setup in the Lab
Flat-Field XUV Spectrometer,
 home built,
for broadband high resolution

 Grazing-Incidence Split Mirror
 for broadband XUV throughput

Time-resolved doubly-excited 2e- dynamics in He
 Experimental data

 XUV
 first

comparison experiment and theory

XUV
first

 quantum-state interference
  phase ( )
 Probing a time-dependent
 superposition state:
  Wavepacket

Measuring the time-dependent phase difference
 of 2s2p and sp23+ autoionization states
 cooperation with Javier Madroñero (Theory, TU München)

 1D cut through atom
 (along laser polarization)

 20 1.0

 location electron 2 [a.u.]
 10
 0.5

 0
 0.0

 -10

 -20
 -20 -10 0 10 20
Ott et al. Nature 2014 location electron 1 [a.u.]

Testing ab-initio theory of e- correlation dynamics
 cooperation: Luca Argenti & Fernando Martín (UAM Madrid, Spain)
 Javier Madroñero (TU Munich)

 experimentally reconstructed (2s2p & sp2,3+ only):
position e- 2

 position e- 1
 ab-initio simulation, all excited states:
position e- 2

 position e- 1
 first experimental observation
 Ott et al. of two-electron wavepacket motion
 Nature 2014

Time-resolved doubly-excited 2e- dynamics in He

 5

 XUV
 first 4
 Time Delay (fs)

 3

 2

 1

 0
 58 59 60 61 62 63 64 65 66
 Photon Energy (eV)
Ott et al. Nature 2014

Time-resolved doubly-excited 2e- dynamics in He

 5

 4
 Time Delay (fs)

 3
 high temporal
 and
 1.2 fs high spectral
 2
 resolution
 20 meV are
 1 required
 simultaneously

 0
 58 59 60 61 62 63 64 65 66
 Photon Energy (eV)
Ott et al. Nature 2014

Hold on, can I ask you a few questions?
 e-
 e-

 What is absorption?
 And how does it respond to intense pulsed light?

Control the electrons, and measure their response
 "Ask" "listen"
 Intensity

 laser
 photon
 energy

Intensity, the control knob
 Autler-Townes doublet tuning from weak perturbative to strong fields
 (Rabi cycling of autoionizing states)

 laser
 photon
 energy

Ott et al. Nature 2014

Intensity, the control knob
 Autler-Townes doublet tuning from weak perturbative to strong fields
 (Rabi cycling of autoionizing states)

 U. Fano
 Phys. Rev.
 q= 124, 1866
 (1961)

 laser
 photon
 energy

Ott et al. Nature 2014

General: coupling of states
 coupling of one to coupling of one to coupling of one to a
 one other state multiple states continuum of states

 What happens when the coupling is ultrashort ?
 1.5 1.5

 Energy E
 Energy E

 1.0 1.0

 0.5
 0.5 0.0 0.1 0.2
 0.0 0.1 0.2
 Coupling Strength  Coupling Strength 
 B
 Rabi oscillation Breit-Rabi U. Fano (1935)
 Phys. Rev. 124, 1866 (1961)
 in strong coupling e.g. Paschen-Back regime
 Nuovo Cim. 12, 154 (1935)
 1 Ω12 Ω13 Ω14 Ω( )
 1 Ω12 Ω21 2 Ω23 Ω24
 Ω21 2 Ω31 Ω32 3 Ω34 Ω( ) 
spectral intensity

 Ω41 Ω42 Ω43 4

 photon energy hn photon energy hn photon energy hn

Resonance absorption in the Time Domain

 Dipole moment 
 free (induction)
 polarization decay
 |1

 Fourier transform
 |0 
 Delta-like Time
 excitation
 Im( ) Lorentzian

 Absorption [OD]
 line shape
refractive index change:
D ( )  ( )
 susceptibility  a (polarizability)

 Energy

Resonance absorption in the Time Domain
Science 340, 716 (2013)
 Duration

 Dipole moment 
 not "kicked"
 Δ "kicked"

 Δ |1
 1
 ∆ = Δ Δ 

 Fourier transform
 ℏ 
 |0
 "kick" Delta-like Time
 laser + excitation
 Im( ) Lorentzian

 Absorption [OD]
 ...it IS a
 line shape
 Fano line shape!
 refractive index change:
 = 2 arg( − )
 D ( )  ( ) Looks like a
 
 susceptibility  a (polarizability) Fano line shape …
 = −cot( )
 2
 Energy

The Fano dipole phase
 Exact mapping from Fano parameter to temporal phase shift 
 cooperation with C. Greene (Purdue), J. Evers and C. Keitel (MPIK)
 ( + )2 10
 σ ~ 2
 +1 'Fano to
 Lorentz'
 = parameter 5

 −1
 Im + 
 exp( ) +
 q

 .
 Fano Fano

 0
 Phase-shifted Lorentzian 'Lorentz
 to Fano'
 ...it IS a
 Fano line shape! -5
 Phase-Shifted Fano
 = 2 arg( − ) turns Lorentz
 and vice versa
 -10
 = −cot( ) 2.0 1.0 0.0 -1.0 -2.0
 2
 phase  
 dipolephase
 dipole
C. Ott et al. Science 340, 716 (2013)

Fano to Lorentz, and Lorentz to Fano
 doubly-excited Helium singly-excited Helium
 originally Fano lineshape originally Lorentzian

 +
 -

 no laser

 +
 -

Laser Intensity:
 2·1012 W/cm2
 Science 340, 716 (2013)

Laser Control of Fano and Lorentzian resonances
 '2s4p' '2s5p' '2s6p' ...

 Absorption (DOD)
 Helium 0.35
 doubly excited turning
 0.30
 (above the original 'Fano'
 0.25
 continuum into 'Lorentz'
 64.4 64.6 64.8 65.0 65.2 65.4
 threshold) Photon energy (eV)

 1s6p 1s7p 1s8p ...
 0.60
 Absorption (DOD)

 Helium 0.40
 turning
 singly excited 0.20
 original 'Lorentz'
 (below the 0.00
 -0.20 into 'Fano'
 continuum -0.40
 24.1 24.2 24.3 24.4 24.5
 threshold) Photon energy (eV)

 = −2.55 ⇒ = 0.24 
 = −cot
 2 Science 340, 716 (2013)

Extracting the laser-induced phase shift
 Cooperation with J. Madronero, L. Argenti, F. Martín

 I=3

 experiment
 I=2

 I=1
 I
 I=0 exp. line shape fit
 atLine
 fixed elapsed
 Shape time,
 Analysis
 e.g. t = 15.6 fs
 φ ~ ΔE Δt
 theo. line shape fit
 theo. phase coeff.
 I=3
ab-initio theory
(Argenti/Martin)
 I=2

 I=1

 I=0 Control of a
 two-electron
 wavepacket
C. Ott et al. Nature 2014

Phase control of "real molecules"

 Can we change the (spectral) shape
 of complex molecules?

Fano control of molecules in the liquid phase
 cooperation with J.-M. Mewes, A. Dreuw, T. Buckup, M. Motzkus@Univ. Heidelberg
Kristina Meyer et al., PNAS (2015)
 Laser Dye IR144 in methanol

 Intensity [arb. units]

Recent measurements in
Aluminum-phthalocyanine-chloride
 Carina da Costa Castanheira et al. (in preparation)
(AlPhCl)

Time-domain, impulsive, resonance control
 Variation of intensity: tuning of coupling strength, phase
Science 340, 716 (2013)
 Atom
 Duration not "kicked"
 2-level system

 Dipole moment
 1
 Δ |1 Δ 
 "kicked"  = ℏ Δ Δ 

 |0

 +
 -

 "kick" Delta-like Time
 laser + excitation
 Lorentz

 Absorption [OD]
 line shape
 Tuning from
 absorption to gain!
 Fano line shape
 ... in the "impulsive" limit!
 (much shorter than the lifetime)
 Energy

Proof-of-Principle: Observation of Resonant Gain
 in singly-excited helium

 +
 -

 absorption
 transformed into
 emission
 within

The Beauty of a Fundamental Mechanism

 Atom
 Duration not "kicked"
 2-level system

 Dipole moment
 1
 Δ |1 Δ 
 "kicked"  = ℏ Δ Δ 

 |0

 +
 -

 "kick" Delta-like Time [fs] [as] [s]
 laser + excitation
 Lorentz

 Absorption [OD]
 line shape
 applies to all
 time scales and
 photon energies... Fano line shape

 Energy [eV][keV][neV]

14.4 keV,
Resonant gain for hard x-rays 57Fe Mössbauer
phase shift at = 0

 FEL or synchrotron pulse 14.412497 keV Spectrometer
 (m)eV bandw. 5 neV bandw. or experiment

 57Fe absorber

 12

 Spectral Intensity [arb. units]
 10

 Laser-like 8

 narrowband 6

 line emission 4

 at hard x-rays 2

 0
 14.4120 14.4122 14.4124 14.4126 14.4128 14.4130

 Photon energy [keV]

Resonant Mössbauer "gain" @
Heeg et al. Science (2017) cooperation with groups of J. Evers, R. Röhlsberger, R. Rüffer
 phase shift at = 0 using a Mössbauer Coherent Control method
 pioneered by Kocharovskaya group
 (Vagizov et al. Nature (2014))

 Avalanche
 FEL or synchrotron pulse 14.412497 keV detector
 (m)eV bandw. 5 neV bandw. array

 57Fe
 absorber on
 57Feabsorber Mössbauer drive
 on piezo drive
 synched to bunch clock 2
 X-ray Transmission

Now: Mechanical motion for phase shift 3

 X-ray Transmission
 => nanosecond response 1

Future: Optical control of phonons 2

 => femtosecond response 0
 0 200 400 600 800
 photon energy - 14.412497 keV [neV]
 1000

 2
 X-ray Transmission

 1
 X-ray pulse ?
 1

 0
 Experiment@ 0 100 200 300 400 500
 0
 0 200 400 600 800 1000 photon energy - 14.412497 keV [neV]
 photon energy - 14.412497 keV [neV]

Towards x-ray frequency combs
 Cooperation with group of C. H. Keitel (MPIK): Cavaletto, Harman et al., Nat. Photonics (2014)
 Liu, Ott, et al., New. J. Phys. (2014)
 Atom
 Duration
 2-level system
 Δ |1 Δ 
 |0

 +
 -

 "kick" "kick" "kick" Delta-like
+...+laser + laser +laser excitation

 Using a pulse train for
 periodic phase shifting ...

 ... creates a
 frequency comb
 precisely locked to
 an atomic transition

Towards x-ray precision metrology
 of highly-charged ions
Crespo group (MPIK)
(image modified from:
Bernitt et al. Nature 492, 225 (2012))

 High-resolution spectroscopy of long-lived
 transitions in highly-charged ions:
 - Precision tests of theories in heavy ions
 (QED, nuclear&relativistic-electronic structure)
 - linking nuclear/electronic x-ray transitions:
 variation of coupling "constants"?

time scales in science

shortest man-made
 flash/pulse of light age of the universe
 ~50 attoseconds 1 second 14 billion years

 electronic human/biological
 timescale timescale
nuclear/atomic molecular geological/astronomical
 timescale timescale timescale

 cameras
 laser pulses

Ultra s l o w dynamics…

 The Fine structure constant:
 fundamental constant ?
 1
 ≈ + ሶ × 
 137.035999139(31)

 Godun et al. PRL 113, 210801 (2014)
 Huntemann et al. PRL 113, 210802 (2014)

sensitivity to a variation
Dzuba, Flambaum, Webb 1
PRL 82, 888 (1999) Δ = ( ) 2 − ( , )
 + 1/2

 Δ 1 |1 Δ 2 |2

 |0 |0

 ( 0 − ) 0 ( 0 + )
 

The highly charged ion (HCI) advantage:
 Enhanced sensitivity to a variation
Dzuba, Flambaum, Webb 1
PRL 82, 888 (1999) Δ = ( ) 2 − ( , )
 + 1/2
 Hg+ : ~ 52 200 cm-1
 = 2 Δ / + . Ir17+: ~ 740 000 cm-1

 Δ 1 |1 Δ 2 |2

 |0 |0

 ( 0 − ) 0 ( 0 + )
 
 At some point,
 controlled/precision VUV/XUV/xray light may be helpful…
 Can we generate VUV frequency combs?

Design of enhancement/HHG cavity

 • Enhancement cavity mounted on high-
 stiffness titanium frame on optical table
 • Pump vibrations absorbed through
 mechanical low-pass filter, factor 10
 reduction in amplitude

VUV-Comb-in-a-box (planning: -3 yrs)
Container enclosure for Lisa Schmöger et al., Science (2015)
Temperature stabilization
Noise isolation HCI deceleration/transfer line
 Mini-EBIT

Comb-Laser (in operation) CryPTEx Paul Trap for Ion Crystal
+ Amplifier (under construction)
 HHG-comb enhancement cavity on stabilized optical table
 mechanically decoupled from vacuum system
 (under construction)
 62/12

VUV-Comb-in-a-box

VUV-Comb-in-a-box
 EBIT Hall Area

Assembling the cavity vacuum chamber

Design of the HHG interaction region

VUV-comb experimental results

25th harmonic observed with high-density jet on fluorescent screen
(Janko Nauta, Jan-Hendrik Oelmann, José Crespo et al. )

VUV-comb experimental results

Next-step VUV-Spectroscopy of HCIs
 • In-vacuo enhancement cavity
 • In 15 µm focus:  1013 W/cm2
 • 100 MHz repetition rate

 Decceleration
 VUV
EBIT frequency
 comb
 RF linear trap

Lisa Schmöger et al., Science (2015)

Acknowledgements
 Quantum Dynamics&Control Division @ MPIK
 Christian Ott
 Robert Moshammer Andreas Kaldun José Crespo
 Claus Dieter SchröterDr. Anne Anne Harth
 Dr. Claus
 Divya Dieter Dr. José
 Bharti Dr. Christian Dr. Robert
 Alexander Blättermann Dr.
 LisaAlexander
 Schmöger
 Kirsten Schnorr Ott Ding Moshammer Hendrik DornBekker
 Harth
 Nicolas Camus Alexander Shobeiry Crespo
 Schröter
 Farshad Thomas
 Hemkumar Srinivas Veit Stooß Sven Bernitt
 Sven Augustin Blättermann Yonghao Mi Chintan Shah
 Patrick Froß Martin Laux Janko Nauta
 Alexander Dorn Peter Micke
 Ana Denhi Xueguang Ren Marc Rebholz
 Frans Schotsch Stepan Dobrodey
 Enliang Wang Max Hartmann Michael Blessenohl
 Georg Schmid Marvin Weyland Paul Birk
 Yifan Liu Julian Stark
 Niels Kurz Lennart Aufleger Jan-Hendrik Oelmann
 Severin Meister Silva Mezinska Patrick Rupprecht
 Hannes Lindenblatt Steffen Kühn
 Deepthy Mootheril Gergana Borisova Alexander Ackermann
 Florian Trost Carina Da Costa Castaneira Sandra Bogen
 Patrizia Schoch Stephan Görttler Michael Rosner
 Alexander Magunia Christian Warnecke
Main Cooperators: Thanks to … and many more !
C. Keitel, J. Evers, Z. Harman, S. Cavaletto and groups (MPIK): Fano physics
C. Greene (Purdue Univ., USA): Fano physics
L. Argenti, F. Martín (Univ. A. Madrid, Spain): 2e- WP, 2D spec
J. Madroñero (TUM&Univ. del Valle, Cali, Colombia): 2e- WP
 Funding:
A. Brown, H. Van der Hart (Queens University, Belfast): 2d spec Neon
J. M. Mewes, A . Dreuw, T. Buckup, M. Motzkus (U. Heidelberg): Liquid phase Grant #PF790
S. Roling, H. Zacharias (Univ. Münster): FLASH FEL Split and Delay
S. Düsterer, R. Treusch, N. Stojanovich,
 G. Brenner, M. Braune (DESY): FLASH FEL exp.
 Heidelberg Center for
A. Attar (UC Berkeley, USA): FLASH exp. Quantum Dynamics
Z.-H. Loh (NTU, Singapore): FLASH exp. X-MuSiC
T. Gaumnitz (ETH Zurich, Switzerland): FLASH exp.

Summary
- Ultrafast Laser quantum control of
 small atomic/molecular quantum systems
 (natural, well-defined "Å-labs")
 for fundamental-physics experiments
- Phase information is key to quantum dynamics
 and can be retrieved by time-"resolved" experiments
- qualitatively new insights into fundamental processes
 (e.g. Fano ↔ Lorentz, Absorption ↔ Gain)
 => New ideas…

Understand, and modify, general mechanisms of Quantum Dynamics
 Unifying Ultrafast Control and Precision Physics