C. Laulhé, S. Ravy, P. Fertey, E. Elkaïm, F. Legrand E. Collet, M. Lorenc, M. Buron-Le Cointe, H. Cailleau Studies of ultrafast structural changes at SOLEIL synchrotron: sub-ns and sub-ps pump-probe diffraction on CRISTAL beamline (CRISTAL beamline - SOLEIL synchrotron) (Institute of Physics - Rennes) Ph. Hollander, S. Hustache, J.-P. Ricaud, P. Féret, T. Moreno (SOLEIL synchrotron) M.-L. Boillot (Institut de Chimie Moléculaire et Matériaux d’Orsay) ANR ULTiMATE – « ULTrafast co-operative and coherent photo-switching of molecular MATErials »

Outline Studies of ultrafast structural changes at SOLEIL synchrotron: sub-ns and sub-ps pump-probe diffraction on CRISTAL beamline I.Pump-probe diffraction: how ? II.Pump-probe diffraction: motivations III.Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 IV.Summary

Outline Studies of ultrafast structural changes at SOLEIL synchrotron: sub-ns and sub-ps pump-probe diffraction on CRISTAL beamline I.Pump-probe diffraction: how ? II.Pump-probe diffraction: motivations III.Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 IV.Summary

Pump-probe diffraction → Natural temporal width of a synchrotron X-ray pulse: 70 ps FWHM → « low-  » mode: 10 ps FWHM (preliminary tests in Dec 2011) → « Slicing » mode: 80 fs FWHM (2014) Making a movie of structural evolutions on the timescales of atomic vibration E ~ 10 meV ↔ T osc ~ 400 fs Following photoinduced structural changes as a function of time Undulator 80 fs // 70 ps Laser h = 1.55 eV ΔtΔt 25 fs RX Toward ultrashort X-ray pulses at SOLEIL synchrotron…

0 m31.25 m36.00 m CRISTAL: future installation for pump-probe experiments 6-circle 4-circle Undulator

0 m31.25 m36.00 m CRISTAL: future installation for pump-probe experiments 6-circle 4-circle m Ti:Sa oscillator + regenerative Ti:Sa amplifier = 800 nm, 25 fs FWHM kHz, 6 1 kHz ~ 1 ms (~ 1 kHz) Undulator

0 m31.25 m36.00 m CRISTAL: future installation for pump-probe experiments 6-circle 4-circle m Ti:Sa oscillator + regenerative Ti:Sa amplifier = 800 nm, 25 fs FWHM kHz, 6 1 kHz ~ 1 ms (~ 1 kHz) Undulator XPAD detector Photon counting enabled on level high of a logic gate Up to 847 kHz frequency 90 ns Delay Delay [ns] Total intensity [a.u.] x 10 6

Outline Studies of ultrafast structural changes at SOLEIL synchrotron: sub-ns and sub-ps pump-probe diffraction on CRISTAL beamline I.Pump-probe diffraction: how ? II.Pump-probe diffraction: motivations III.Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 IV.Summary

Laser-induced phenomena in condensed matter  t : few fs → Out-of-equilibrium states → Decoupled degrees of freedom t = 0 : laser driven electronic transition = 800 nm ↔ E = 1.55 eV

t < few ps : coherent phonons µsnspsfs Laser-induced phenomena in condensed matter  t : few fs → Out-of-equilibrium states → Decoupled degrees of freedom t = 0 : laser driven electronic transition = 800 nm ↔ E = 1.55 eV Diffracted intensity (a.u.) Time (ps) La 0.42 Ca 0.58 MnO 3 P. Beaud et al., PRL (2009) Sudden shift of the equilibrium coordinates of the ions: Displacive excitation (5 3/2 2) Coherent phonons

t < few ps : coherent phonons µsnspsfs Laser-induced phenomena in condensed matter  t : few fs → Out-of-equilibrium states → Decoupled degrees of freedom t = 0 : laser driven electronic transition = 800 nm ↔ E = 1.55 eV Diffracted intensity (a.u.) Time (ps) La 0.42 Ca 0.58 MnO 3 P. Beaud et al., PRL (2009) Sudden shift of the equilibrium coordinates of the ions: Displacive excitation (5 3/2 2) Coherent phonons t < few 100 ps : ultrafast phase transitions P. Baum et al., Science (2007) VO 2 Photoinduced ph. tr. T ˂ T c T ˃ TcT ˃ Tc t0t0 t1t1 t2t2 Temperature Laser excitation t0t0 t1t1 t2t2

t < few ps : coherent phonons µsnspsfs Laser-induced phenomena in condensed matter  t : few fs → Out-of-equilibrium states → Decoupled degrees of freedom t = 0 : laser driven electronic transition = 800 nm ↔ E = 1.55 eV Diffracted intensity (a.u.) Time (ps) La 0.42 Ca 0.58 MnO 3 P. Beaud et al., PRL (2009) Sudden shift of the equilibrium coordinates of the ions: Displacive excitation (5 3/2 2) Coherent phonons t < few 100 ps : ultrafast phase transitions P. Baum et al., Science (2007) VO 2 Photoinduced ph. tr. T ˂ T c T ˃ TcT ˃ Tc t0t0 t1t1 t2t2 Temperature Laser excitation t0t0 t1t1 t2t2 t in range [10 fs ps]: lattice dynamics driven by interactions with electronic degrees of freedom

µsnspsfs Laser-induced phenomena in condensed matter  t : few fs → Out-of-equilibrium states → Decoupled degrees of freedom t = 0 : laser driven electronic transition = 800 nm ↔ E = 1.55 eV Coherent phonons Photoinduced ph. tr. t ~ ns : propagation of deformation waves  Phonon creation: local increase of temperature  Stressed regions: propagation of a strain wave compressive strain Strain waves Heat diff. t ~ µs : laser-induced heat diffusion  Heat diffusion: homogeneisation of temperature

µsnspsfs Laser-induced phenomena in condensed matter  t : few fs → Out-of-equilibrium states → Decoupled degrees of freedom t = 0 : laser driven electronic transition = 800 nm ↔ E = 1.55 eV Coherent phonons Photoinduced ph. tr. t ~ ns : propagation of deformation waves  Phonon creation: local increase of temperature  Stressed regions: propagation of a strain wave compressive strain Strain waves Heat diff. t ~ µs : laser-induced heat diffusion  Heat diffusion: homogeneisation of temperature t in range [100 ps - 10 µs]: Laser induced strain waves and heat diffusion - control of the electronic properties ??

Outline Studies of ultrafast structural changes at SOLEIL synchrotron: sub-ns and sub-ps pump-probe diffraction on CRISTAL beamline I.Pump-probe diffraction: how ? II.Pump-probe diffraction: motivations III.Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 IV.Summary

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 [TPA (FeIII) TCC] Tris(2-pyridylméthyle) 3,4,5,6-tetrachlorocatecholate Lattice ↔ cooperative effects? [TPA (FeIII) TCC] PF 6

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 [TPA (FeIII) TCC] Tris(2-pyridylméthyle) 3,4,5,6-tetrachlorocatecholate Lattice ↔ cooperative effects? [TPA (FeIII) TCC] PF 6 M. Lorenc et al., PRL (2009) Time-resolved structure determination at 180 K:  : fraction of molecules in the HS state Unit cell parameter a : elastic deformations Debye-Waller factor B: crystal temperature

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 [TPA (FeIII) TCC] Tris(2-pyridylméthyle) 3,4,5,6-tetrachlorocatecholate Lattice ↔ cooperative effects? [TPA (FeIII) TCC] PF 6 M. Lorenc et al., PRL (2009) Time-resolved structure determination at 180 K:  : fraction of molecules in the HS state Unit cell parameter a : elastic deformations Debye-Waller factor B: crystal temperature 1 Photoinduced effects in [TPA Fe(III) TPP] PF 6 : 1)Laser induced switching of molecules

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 [TPA (FeIII) TCC] Tris(2-pyridylméthyle) 3,4,5,6-tetrachlorocatecholate Lattice ↔ cooperative effects? [TPA (FeIII) TCC] PF 6 M. Lorenc et al., PRL (2009) Time-resolved structure determination at 180 K:  : fraction of molecules in the HS state Unit cell parameter a : elastic deformations Debye-Waller factor B: crystal temperature 1 2 Photoinduced effects in [TPA Fe(III) TPP] PF 6 : 1)Laser induced switching of molecules 2)Deformation wave propagation

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 [TPA (FeIII) TCC] Tris(2-pyridylméthyle) 3,4,5,6-tetrachlorocatecholate Lattice ↔ cooperative effects? [TPA (FeIII) TCC] PF 6 M. Lorenc et al., PRL (2009) Time-resolved structure determination at 180 K:  : fraction of molecules in the HS state Unit cell parameter a : elastic deformations Debye-Waller factor B: crystal temperature Photoinduced effects in [TPA Fe(III) TPP] PF 6 : 1)Laser induced switching of molecules 2)Deformation wave propagation 3)Heat diffusion in the crystal

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 [TPA (FeIII) TCC] Tris(2-pyridylméthyle) 3,4,5,6-tetrachlorocatecholate Lattice ↔ cooperative effects? [TPA (FeIII) TCC] PF 6 M. Lorenc et al., PRL (2009) Time-resolved structure determination at 180 K:  : fraction of molecules in the HS state Unit cell parameter a : elastic deformations Debye-Waller factor B: crystal temperature Photoinduced effects in [TPA Fe(III) TPP] PF 6 : 1)Laser induced switching of molecules 2)Deformation wave propagation 3)Heat diffusion in the crystal 4)Relaxation

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 Experimental setup

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 Experimental setup kphi X-rays 002 c kphi Rocking curve measurements Ewald sphere kphi-scan ↔ Imaging the 002 Bragg spot in 3D Bragg spot extensions along a and b: Spread of (002) lattice plane tiltings in the a and b directions a c b

Test experiment: photoinduced effects in [TPA Fe(III) TCC] PF 6 ∑

∑ ∑

∑ ∑ Two characteristic timescales: - Few 100 ns after excitation: peak broadening without profile change - Few µs after excitation: peak broadening with apparition of a tail Two lattice plane deformation cycles: - During step 2) propagation of deformation waves - During step 3) heat diffusion

Summary First time-resolved experiment at the CRISTAL beamline [ns resolution] [TPA Fe(III) TCC] PF6: lattice plane deformations in laser-induced transient states  Improvement of the temporal resolution: - November 2011: reception of a fs laser → 70 ps resolution - Year 2012: optimization of the low-alpha mode of operation → 10 ps resolution - Year 2014: « slicing » mode of operation → 100 fs resolution Study of the interplays between lattice and electronic degrees of freedom Control of electronic properties in molecular crystals

undulator laser wiggler bending magnet e-beam 70ps 75fs Sub-ps resolution: slicing Time resolution ~ 100 fs wiggler electron bunch (70 ps) Laser pulse: 25 fs, few mJ 2.5 kHz, 800 nm Exchange of energy between electrons and IR photons bending magnet In the “sliced” zone, the electrons have energies spanning the range [E-ΔE ; E+ ΔE]. They will be spatially dispersed during their pass in the bending magnet. electron bunch (75 fs) Seminal paper : Zholents and Zolotorev, PRL (1996) Available at Bessy, SLS, ALS Laser