Introduction Pump & Probe Warm Dense Matter Coherent Diffraction Imaging Four Wave Mixing

Transcript

1 Dinamica ultraveloce nei materiali e negli stati estremi della materia studiata con i FEL Introduction Pump & Probe Warm Dense Matter Coherent Diffraction Imaging Four Wave Mixing C. Masciovecchio Elettra-Sincrotrone Trieste, Basovizza, Trieste I-34149

2 Peak brilliance = photons/s/mrad 2 /mm 2 /0.1%bandwidth Free Electron Lasers

3 Free Electron Lasers Imaging high Spatial Resolution (~ l), fixed target imaging, particle injection imaging,... Dynamics four wave mixing (nanoscale), warm dense matter, extreme condition, Resonant Experiments XANES (tunability), XMCD (polarization), chemical mapping,

4 Pump & Probe The pump pulse produces a change in the sample - stimulate a chemical reaction - non-equilibrium states - extreme thermodynamic conditions - ultrafast demagnetization - coherent excitations -... Signal that is monitored by the probe pulse

5 Free Electron Lasers SASE (Self Amplified Spontaneous Emission) Seeded FEL L. H. Yu et al., PRL (2003)

6 Dt < 100 fs Flux ~ ph/pulse E ~ ev Total Control on Pulse Energy Time Shape Polarization

7 FEL-pump & Laser-probe Signal GaAs Jitter has been measured to be < 7 fs WORLD RECORD!! DR/R M. Danailov et al., submitted to Opt. Express Time (sec) x 10-12

8 Warm Dense Matter interior of large planets and stars

9 F. Bencivenga et al., (2014)

10 Coherent Diffraction Imaging 5 mm Nanolithographic Object Diffraction Pattern Reconstructed Image Resonant CDI at Co M edge (Co/Pt ML) λ = 23.5 nm λ = 21.0 nm λ = 20.8 nm λ = 20.6 nm λ = 20.4 nm F. Capotondi et al. Rev. Scient. Instr. (2013)

11 Controlling ultrafast demagnetization using localized optical excitation S. Eisebitt et al, submitted to PRL

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13 l 2 l 1pump D (ev) F (J/cm 2 ) F. Bencivenga et al., Farad. Discussion (2014)

14 Four Wave Mixing at FEL s 1 k 1 2 k 2 3 k 3 4 k 4 Four Wave Mixing techniques are: Stimulated Raman Gain Spectroscopy, Inverse Raman Effect Spectroscopy, Photon Echo and Raman Induced Kerr Effect Spectroscopy, Femtosecond Stimulated Raman Scattering and Coherent Antistokes Raman Scattering (CARS) Measure the coherence between the two different sites tuning energies and time delay makes possible to chose where a given excitation is created, as well as where and when it is probed delocalization of electronic states and charge/energy transfer processes.

15 Conclusions FERMI allows pushing time resolved spectroscopies in the femtosecond time domain with unprecedented energy stability, jitter, tunability, pulse coherence, Warm Dense Matter Ultrafast Demagnetization Four Wave Mixing has the potential to become very valuable technique for the study of transport properties, intra-molecular dynamics and non-linear material responses

16 Aknowlegments F. Parmigiani L. Giannessi M. Danailov M. Zangrando M. Kiskinova F. Casolari F. Bencivenga E. Principi A. Battistoni F. Capotondi M. Manfredda A. Gessini E. Giangrisostomi R. Cucini E. Pedersoli R. Mincigrucci