John T. Costello National Centre for Plasma Science & Technology (NCPST)/ School of Physical Sciences, Dublin City University (Very) Small Quantum Systems in Intense Bichromatic Fields -(and some thoughts on pump-probe) Small Quantum Systems Workshop, Aarhus, Oct , 2008

2008 Membership- LIXAM (Orsay, France) D. Cubaynes, D Glijer, M. Meyer DESY (Hamburg, Germany) S. Düsterer, H. Redlin, W-B Li, J. Feldhaus Dublin City University (Ireland) J. Dardis, P. Hayden, P. Hough, E. T. Kennedy, V. Richardson and J. T. Costello Formerly QUB. C. Lewis et al. Two-Colour ‘FLASH’ Collaboration Small Quantum Systems Workshop, Aarhus, Oct , 2008 Photoionization Experiments with the Ultrafast EUV Laser FLASH - Free Electron Laser in Hamburg J T Costello, J Phys Conf Ser 88 Art No (2007)

Small does not mean simple (especially in intense fields) Two colour laser experiments on SQS very much in vogue in the 1970s & 1980s So what’s new (possible) with FLASH - (LCLS) - XFEL ? What do we need from the FEL and the ‘synchronised’ optical laser(s) ? Train of thought………. Small Quantum Systems Workshop, Aarhus, Oct , 2008

SQS in Intense Fields Small Quantum Systems Workshop, Aarhus, Oct , 2008 Corkum P B and Krausz F, Attosecond Science Nature Physics (2007) In vogue NOW ! ‘Knight Doublet’ P L Knight, J. Phys. B: AMP 11 L 511 (1978) In vogue THEN !

Atoms (Molecules) in Intense XUV + NIR Fields Coherent photoionization processes in superposed fields Optically probing fragments in XUV dissociated H 2 Next steps - Two Colour Resonant Processes Technological Developments for Next Phase Bichromatic Laser Field-SQS Experiments SQS in Bichromatic Fields Small Quantum Systems Workshop, Aarhus, Oct , 2008 M Meyer yesterday - FOCUS ON

Small Quantum Systems Workshop, Aarhus, Oct , 2008 SQS in Bichromatic Fields Proposal 1 - Quantum Optics with Unbound States Loh, Greene & Leone Chem. Phys (2008) EIT & coherent population transfer (CPT) - optical switching, slow light (storage) etc. Probe Pump LICS Coherent Population Transfer with Autoionising States (AIS) Karapanagioti et al. PRL (1995)

Small Quantum Systems Workshop, Aarhus, Oct , 2008 SQS in Bichromatic Fields Proposal 1 - Quantum Optics with Unbound States Loh, Greene & Leone Chem. Phys (2008) First? demonstartion of EUV transparency switching Karapanagioti et al. PRL (1995) Autler-Townes with AIS !

Small Quantum Systems Workshop, Aarhus, Oct , 2008 SQS in Bichromatic Fields Proposal 1 - Quantum Optics with Unbound States Conventional lasers: QO with valence electron - continuum probes FLASH: QO with sub-valence electron - continuum probes (e.g., Meyer Kr, 3d d 9 4d proposal) XFEL: QO with core electron - continuum probes (e.g., Duesterer et al., LCLS - Ne, 1s 2 - 1snp proposal) Summary: EIT & CPT with X-rays and autoionising states

Small Quantum Systems Workshop, Aarhus, Oct , 2008 SQS in Bichromatic Fields Proposal 1 - Quantum Optics with Unbound States (X)FEL: Wavelength tunable and well characterised (shot to shot) - wavelength, bandwidth, spectral dist., energy, etc. Optical laser(s): Ideally two or more tunable OPAs with 5+ picosecond duration (to overcome 0.5 ps jitter problem). For sidebands must be UV laser (h >4 eV) as BW of LCLS & XFEL will be 0.2% (4eV at 2 KeV) Detectors: We want everything [Ions, electrons, photons (IR - XUV), spin and polarisation (Stokes parameters) and all in co-incidence for ‘complete experiments’ - A. Wolf question Summary: EIT & CPT with X-rays and autoionising states Note: Not to forget Moshammer and Quantum-Zeno Effect (if field is intense)

Small Quantum Systems Workshop, Aarhus, Oct , 2008 SQS in Bichromatic Fields Proposal 1 - Quantum Optics with Unbound States (X)FEL: Wavelength tunable and well characterised (shot to shot) - wavelength, bandwidth, spectral dist., energy, etc. Optical laser(s): Ideally two or more tunable OPAs with 5+ picosecond duration (to overcome 0.5 ps jitter problem). For sidebands must be UV laser (h >4 eV) as BW of LCLS & XFEL will be 0.2% (4eV at 2 KeV) Detectors: We want everything [Ions, electrons, photons (IR - XUV), spin and polarisation (Stokes parameters) and all in co-incidence for ‘complete experiments’ - A. Wolf question Summary: EIT & CPT with X-rays and autoionising states Note: Not to forget Moshammer and Quantum-Zeno Effect (if field is intense)

Small Quantum Systems Workshop, Aarhus, Oct , 2008 SQS in Bichromatic Fields Proposal 2 - Post collision probes of simple molecules

M Meyer et al. PRA R (2006) P Radcliffe, et al., APL (2007) Jitter - Problem for probing prompt dissociation dynamics…… ~500 fs New ultrafast EUV-modulated optical-reflectivity methods: 1.C. Gahl et al., Nature Photonics (2008) 2.T. Maltezopoulos et al., New J Phys 10 Art. No (2008) SQS in Bichromatic Fields Primary phase - better to use XUV- XUV Pump-Probe Setup proposed by Moshammer-Vrakking. Sub-fs resolution…………. Evolution of Atomic Fragments - Here we can use pump-probe with OPAs synchronised to (X)FEL (ps) And fluorescence with ICCD spectroscopy for bound states (ns)

Further Steps for AMOP at FELs - Solutions to the timing jitter problem ? Nature Physics March 2008 Small Quantum Systems Workshop, Aarhus, Oct , 2008

Even Further Steps for AMOP at XFEL - Attosecond Pulses ? Small Quantum Systems Workshop, Aarhus, Oct , 2008

R P Madden and K Codling PRL (1963) ‘New Knobs’ FEL Frequency FEL Intensity Tunable (X)FEL - Driving autoionising transitions in intense XUV fields Small Quantum Systems Workshop, Aarhus, Oct , 2008

Next Phase (FLASH to XFEL) 1.To date we have looked only at one and two colour non- resonant photoionization processes 2.FEL tunable and so we can explore resonant two colour processes where inner shell electrons dominate - QO in the XUV/X-ray with AIS…….. 3.Study fragmentation and ionization from vibrationally excited/selected wavepackets in simple molecules 4.Beyond 2010: Seeding, fs jitter and attosecond pulses (XFEL): Photoionization - Dissociation Imaging Dynamics Small Quantum Systems Workshop, Aarhus, Oct , 2008

New ‘Plasma-SQS’ Targets ? Small Quantum Systems Workshop, Aarhus, Oct , 2008 New targets - Colliding Plasmas ? Atomic Ca/Ca + - Emission 423 nm Laser Pulse Energy: mJ/ beam Laser Pulse duration: ns Focal Spot Size:~ 100  m Irradiance: W.cm -2 Warm (Moderately) Dense Matter H Luna, K D Kavanagh & J T Costello, J Appl Phys 101, Art No (2007)

For Pump-Probe at FLASH - XFEL Small Quantum Systems Workshop, Aarhus, Oct , Please, please, please include multiple OPA beamlines with fs - ps variable pulse duration and UV - FIR tunability 2.Optical tunability can compensate for the fact that FELs are often locked on ‘sweet spot’ wavelengths. 3.We want everything [ions, electrons, photons (IR - XUV), spin and polarisation (Stokes parameters) and all in co- incidence for ‘complete experiments’] - A. Wolf again….. 4.FEL diagnostics, diagnostics, diagnostics,…….. 5.State of the art (but reliable) optical laser sources/ diagnostics at the XFEL => XFEL development phase OK !