Who I am

I am the principal investigator of the Non-Periodic Imaging task at Stanford PULSE Institute, an independent laboratory of Stanford University and a staff scientist at SLAC National Accelerator Laboratory . We lead the effort on X-ray imaging of ultrafast atomic motion and transient structure in molecules, and study the nature of short wavelength strong field interaction with bound and free electrons. My goal is to develop and apply experimental and computational ultrafast scattering approaches to image quantum dynamics in real space to study and understand mechanisms that involve structural dynamics and electronic motion in photoexcited molecules of increased complexity and in complex environments. I received my PhD in Physics from the Weizmann Institute of Science, where I worked with Prof. Yaron Silberberg on coherent control, strong field interaction, nonlinear spectroscopy, and quantum optics.

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Ultrashort CV

Professional Experience:

SLAC National Accelerator Laboratory, Staff Scientist, 2022-today
SLAC National Accelerator Laboratory, Associate Staff Scientist, 2017-2022
SLAC National Accelerator Laboratory, Research Associate, 2014-2017
Stanford University, Applied Physics, Postdoctoral fellow, 2011-2014

Education:

Weizmann Institute of Science, PhD Physics, 2009
Weizmann Institute of Science, M.Sc Biological Physics, 2004
Hebrew University, Jerusalem, Israel, B.Sc Physics, 2001

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Research

Studying matter and dynamics at the level of electrons and atoms requires imaging structures and motions in the sub-Ångstrom to nanometer and attosecond to picosecond scales, as in these ranges the fundamental properties of materials and physical mechanisms are established. State-of-the-art instruments such as X-ray free electron lasers, and ultrafast electrons are emerging tools that transform several fields of science because they access the atomic length and time scales without affecting the sample. Here we develop ultrafast scattering approaches to image quantum dynamics in real space to study and understand the interplay between photoabsorption, coherent electronic and nuclear motions, decoherence and energy redistribution.
Imaging coherent dynamics in complex environments

We led the first high-energy (18 keV) ultrafast X-ray scattering experiment in solution aiming to understand the role of coherent solute motions in complex environments on solvation and energy transfer dynamics. Applying advanced imaging methods, we decompose ultrafast solvation dynamics into specific changes in the solute and solute-solvent pair distribution function and directly trace the spatiotemporal shape of coherent vibrational wavepacket motions of different atom-pairs that take place simultaneously. Comparing to hybrid QM/MM trajectory simulations we retrieve the ground and excited state pair density distributions of the isotropic and anisotropic solute and solute-solvent terms in sub-Ångstrom resolutions. Combining high-energy X-rays with extreme brilliance and time resolution enables us to robustly characterize the non-equilibrium properties of molecules with atomic-scale resolution in time and space, presenting a significant opportunity to advance the discovery of design rules for controlling excited states.

Observing in Real Space the Dynamics of Transition Metal Complexes

The photodissociation dynamics of transition metal carbonyls are crucial for understanding catalytic intermediates, but their ultrafast structural dynamics have been difficult to capture. Using ultrafast X-ray scattering, we obtained the immediate photochemical reactions of Fe(CO)5, observing oscillations in atomic distances and a rotating CO ligand release in the axial direction after photoexcitation. We also observe a secondary CO release and provides detailes into the energy redistribution within the molecule, significantly advancing the understanding of the structural dynamics in transition metal catalysis.

Super-resolution in Ultrafast Scattering

Direct real-space recovery of general atomic motions is still mostly limited to signal interpretation in reciprocal space using system-dependent simulations, due to the insufficient scattering vector and photon energies available. We show how to extend super-resolution methods that transformed microscopy and bio-imaging, to the challenging case of ultrafast scattering, where traditional imaging optics, engineered single-emitters, or access to multiple scattering and high spatial frequencies are not available. We introduce theoretically and demonstrate experimentally an inversion and super-resolution method that allows the recovery of multiple sub-diffraction-limit spaced atomic distances from noisy signals. The approach directly brings real-space atomic resolutions to the ultrafast timescale, where often only spectroscopic information is recorded.

Imaging Strong-Field Induced Motion using High-Order Anisotropy X-ray Scattering

We have demonstrated the first ultrafast X-ray scattering of strongly driven molecular systems and analysis of high-order anisotropic components of the scattering signal, up to four-photon absorption. We outlined a method to analyze the scattering signal connecting the high-order anisotropy measured by the detector and the theoretical anisotropy scattering curves. We experimentally observed a multitude of dissociation and vibration motions simultaneously arising from various multiphoton transitions and used the anisotropy information of the scattering signal to disentangle the different processes and assign their dissociation velocities on the Ångström and femtosecond scales de-novo. The approach we demonstrated opens the way to image strong-field-induced motions directly.

Energy Resolved Scattering

We are developing methods to resolve and control the bandwidth of x-ray scattering signals, which will be a significant step forward in uncovering electronic motions in photo-excited systems. We have led beamtime in SSRL, collaborating with H. Yavas (LCLS), to characterize the energy resolution and fidelity trade-offs of a novel non-uniformly segmented spherical crystal analyzer that we have designed and fabricated, measuring the bandwidth response as a function of various properties of the analyzer segments, such as their area and aspect ratios.

Past Projects:

Singularities in strong-field dissociation

We study two types of singularities in strong field dissociation, the Light-induced conical intersection (LICI), and the cusp-type angular focusing. Conical intersections (CI) are natural degeneracies between Born-Oppenheimer surfaces that facilitate non-radiative energy transfer between electronic states, and play an important role in molecular dynamics. LICIs are degeneracies in the light-induced dressed state basis of the Born-Oppenheimer surfaces. Unlike ordinary CIs, the LICIs can be realized even in diatomic molecules, because the laser polarization adds an additional degree of freedom. We have demonstrated the effect LICI has on the driven diatomic system (H2+), manifested in angular distribution modulations that result from the topological singularity induced by intense laser pulses. A different type of singularity that is under study is a cusp-type catastrophe that originates from angular focusing of nonresonant vibration states. When these states are coupled to strong fields, the cusp is observed in angle-resolved H2+ photo-dissociation over a broad kinetic energy release range.

Attosecond dynamics in above-threshold ionization

We have measured the relative phase of different above-threshold ionization (ATI) peaks in a manner that is analogous to the XUV single photon phase measurements that employ RABBITT or the attosecond streak camera. This is multi-path interference of adjacent ATI peaks by a weak probe field at half the frequency. Sideband peaks appear due to absorption or emission of a single probe photon from adjacent ATI levels. We were able to resolve phase delays in ATI as function of the probe field delay to attosecond accuracy. We are expanding these observations to incorporate more detailed angular information, and also to study different regimes of strong-field ionization

Strong field atomic and molecular physics with velocity map imaging

We developed velocity map imaging modalities and analysis tools to study various aspects of strong field interaction. These methods were used to study attosecond time-resolved photoelectron holography and laser induced electron diffraction, to discover angle resolved phase-shifts in photoionization, uncover electron-molecular-frame dynamics in atomic and molecular systems, and for attosecond X-ray pulse characterization.

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Publications

Google Scholar | Academia.edu

Characterization of Deformational Isomerization Potential and Interconversion Dynamics with Ultrafast X-ray Solution Scattering
N. E. Powers-Riggs, et al
J. Am. Chem. Soc. , 817, 4 (2024)
Real-Space Inversion and Super-Resolution of Ultrafast Scattering
A. Natan
Phys. Rev. A, 107 , 023105 (2023)
Transient vibration and product formation of photoexcited CS2 measured by time-resolved X-ray scattering
I. Gabalski, et al
The Journal of Chemical Physics (2022)
Attosecond Coherent Electron Motion in Auger-Meitner Decay
S. Li, et al
Science, 375, 285-290 (2022)
Time-resolved diffraction: general discussion
F Allum, K Amini, M Ashfold, D Bansal, RJF Berger, M Centurion, G Dixit, et al
Faraday Discuss. 228, 161-190 (2021)
Time-resolved ultrafast spectroscopy: general discussion
M Ashfold, M Chergui, I Fischer, L Ge, G Grell, M Ivanov, A Kirrander, et al
Faraday Discuss. 228, 329-348 (2021)
Ultrafast X-ray science: general discussion
F Allum, F Calegari, SM Cavaletto, M Centurion, G Dixit, E Fasshauer, et al
Faraday Discuss. 228, 597-621 (2021)
Disentangling the Sub-Cycle Electron Momentum Spectrum in Strong-Field Ionization
N. Werby, A. Natan, R. Forbes, P. H. Bucksbaum
Phys. Rev. Research 3, 023065 (2021)
Resolving Multiphoton Processes with High-Order Anisotropy Ultrafast X-ray Scattering
A. Natan, A. Schori, G. Owolabi, J. P. Cryan, J. M. Glownia, P. H. Bucksbaum
Faraday Discuss. 228, 123-138 (2021)
Electronic population transfer via impulsive stimulated x-ray Raman scattering with attosecond soft-x-ray pulses
J. T. O’Neal, et al
Phys. Rev. Lett. 125 (7) 073203 (2020)
Characterizing multiphoton excitation using time-resolved X-ray scattering
P. H. Bucksbaum, M. R. Ware, A. Natan, J. P. Cryan, J. M. Glownia
Phys. Rev. X 10 (1), 011065 (2020)
X-ray diffractive imaging of controlled gas-phase molecules: Toward imaging of dynamics in the molecular frame
T. Kierspel, A. Morgan, J. Wiese1, T. Mullins, A. Aquila, A. Barty, R. Bean, R. Boll, S. Boutet, P. Bucksbaum, H. N. Chapman, L. Christensen, A. Fry, M. Hunter, J. E. Koglin, M. Liang, V. Mariani, A. Natan, J. Robinson, D. Rolles, A. Rudenko, K. Schnorr, H. Stapelfeldt, S. Stern, J. Thøgersen, C. H. Yoon, F. Wang, and J. Küpper
J. Chem. Phys. 152, 084307, (2020)
Attosecond transient absorption spooktroscopy: a ghost imaging approach to ultrafast absorption spectroscopy
T. Driver, S. Li, , E. G. Champenois, J. Duris, D. Ratner, T. J Lane, P. Rosenberger, A. Al-Haddad, V. Averbukh, T. Barnard, N. Berrah, C. Bostedt, P. H. Bucksbaum, R. Coffee, L. F. DiMauro, L. Fang, D. Garratt, A. Gatton, Z. Guo, G. Hartmann, D. Haxton, W. Helml, Z. Huang, A. LaForge, A. Kamalov, M.F. Kling, J. Knurr, M. Lin, A. A. Lutman, J.P. MacArthur, J. P. Marangos, M. Nantel, A.Natan, R. Obaid, J. T. O'Neal, N. H. Shivaram, A. Schori, P. Walter, A. L. Wang, T.J.A. Wolf, A. Marinelli, and J. P. Cryan
Phys. Chem. Chem. Phys., (2020)
Tunable isolated attosecond X-ray pulses with gigawatt peak power from a free-electron laser
J. Duris, S. Li, T. Driver, E. G. Champenois, J. P. MacArthur, A. A. Lutman, Z. Zhang, P. Rosenberger, J. W. Aldrich, R. Coffee, G. Coslovich, F. Decker, J. M. Glownia, G. Hartmann, W. Helml, A. Kamalov, J. Knurr, J. Krzywinski, M. Lin, J. P. Marangos, M. Nantel, A. Natan, J. T. O’Neal, N. Shivaram, P. Walter, A. L. Wang, J. J. Welch, T. J. A. Wolf, J. Z. Xu, M. F. Kling, P. H. Bucksbaum, A. Zholents, Z. Huang, J. P. Cryan, and A. Marinelli
Nature Photonics 14, 30–36 (2020)
On the limits of observing motion in time-resolved X-ray scattering
M. R. Ware, J. M. Glownia, A. Natan, J. P. Cryan, and P. H. Bucksbaum
Phil. Trans. R. Soc. A . 377, 20170477 (2019)
A co-axial velocity map imaging spectrometer for electrons
S. Li, E. G. Champenois, R. Coffee, Z. Guo, K. Hegazy, A. Kamalov, A. Natan, J. O’Neal1, T. Osipov, M. Owens III, D. Ray, D. Rich, P. Walter, A. Marinelli, and J. P. Cryan
AIP Advances 8, 115308 (2018)
Attosecond time-resolved photoelectron holography
G. Porat, G. Alon, S. Rozen, O. Pedatzur, M. Krüger, D. Azoury, A. Natan, G. Orenstein, B. D. Bruner, M. J. J. Vrakking, and N. Dudovich
Nature Communications 9, 2805 (2018).
Characterizing isolated attosecond pulses with angular streaking
S. Li, Z. Guo, R. N. Coffee, K. Hegazy, Z. Huang, A. Natan, T. Osipov, D. Ray, A. Marinelli, and J. P. Cryan
Optics Express 26, Issue 4, 4531-4547 (2018)
Imaging the Breakdown of Molecular Frame Dynamics through Rotational Uncoupling
L. J. Zipp, A. Natan, and P. H. Bucksbaum
Phys. Rev. A 95, 061403(R) (2017)
Probing ultrafast ππ*/nπ* internal conversion in organic chromophores via K-edge resonant absorption
T.J.A. Wolf, R.H. Myhre, J.P. Cryan, S. Coriani, R.J. Squibb, A. Battistoni, N. Berrah, C. Bostedt, P. Bucksbaum, G. Coslovich, R. Feifel, K.J. Gaffney, J. Grilj, T.J. Martinez, S. Miyabe, S.P. Moeller, M. Mucke, A. Natan, R. Obaid, T. Osipov, O. Plekan, S. Wang, H. Koch, M. Gühr
Nature Communications 8, 29 (2017).
Self-referenced coherent diffraction x-ray movie of Angstrom-and femtosecond-scale atomic motion
J.M. Glownia*, A. Natan*, J.P. Cryan, R. Hartsock, M. Kozina, M.P. Minitti, S. Nelson, J. Robinson, T. Sato, T. van Driel, G. Welch, C. Weninger, D. Zhi, P.H. Bucksbaum, (*equally contributed)
Phys. Rev. Lett. 117 153003 (2016)
Observation of Quantum Interferences via Light-Induced Conical Intersections in Diatomic Molecules
A. Natan, M.R. Ware, V. S. Prabhudesai, U. Lev, B.D. Bruner, O. Heber, P.H. Bucksbaum
Phys. Rev. Lett. 116 143004 (2016)
Auger electron and photoabsorption spectra of glycine in the vicinity of the oxygen K-edge measured with an X-FEL
A. Sanchez-Gonzalez, T. R. Barillot, R. J. Squibb, P. Kolorenč, M. Agaker, V. Averbukh, M. J. Bearpark, C. Bostedt, J. D. Bozek, S. Bruce, S. Carron Montero, R. N. Coffee, B. Cooper, J. P. Cryan, M. Dong, J. H. D. Eland, L. Fang, H. Fukuzawa, M. Guehr, M. Ilchen, A. S. Johnsson, C. Liekhus-S, A. Marinelli, T. Maxwel, K. Motomura, M. Mucke, A. Natan, T. Osipov, C. Östlin, M. Pernpointner, V. S. Petrovic, M. A. Robb, C. Sathe, E. R. Simpson, J. G. Underwood, M. Vacher, D. J. Walke, T. J. A. Wolf, V. Zhaunerchyk, J-E Rubensson, N. Berrah, P. H. Bucksbaum, K. Ueda, R. Feifel, L. J. Frasinski and J. P. Marangos.
J. Phys. B. 48 (23), 234004 (2015)
Strongly aligned gas-phase molecules at free-electron lasers
T. Kierspel, J. Wiese, T. Mullins, J. Robinson, A. Aquila, A. Barty, R. Bean, R. Boll, S. Boutet, P. Bucksbaum, H. N. Chapman, L. Christensen, A. Fry, M. Hunter, J. E. Koglin, M. Liang, V. Mariani, A. Morgan, A. Natan, V. Petrovic, D. Rolles, A. Rudenko, K. Schnorr, H. Stapelfeldt, S. Stern, J. Thøgersen, C. Hong Yoon, F. Wang, S. Trippel, J. Küpper
J. Phys. B. 48 (20), 204002 (2015)
Ultrafast Isomerization Initiated by X-Ray Core Ionization
C. E. Liekhus-Schmaltz, I. Tenney, T. Osipov, A. Sanchez, A. Belkacem, N. Berrah, R. Boll, C. Bomme, C. Bostedt, J. D. Bozek, S. Carron, R. Coffee, J. Devin, B. Erk, L. Fang, K. Ferguson, R. W. Field, L. Foucar, L. Frasinski, J. M. Glownia, M. Gühr, A. Kamalov, J. Krzywinski, H. Li, J. P. Marangos, T. Martinez, B. K. McFarland, S. Miyabe, B. Murphy, A. Natan, D. Rolles, A. Rudenko, M. Siano, E. Simpson, L. Spector, M. Swiggers, D. Walke, S. Wang, T. Webber, P. H. Bucksbaum, and V. S. Petrovic
Nature Communications 6 , 8199 (2015).
Quantum control of photodissociation using intense, femtosecond pulses shaped with third order dispersion
U. Lev, L. Graham, C.B. Madsen, I. Ben-Itzhak, B.D. Bruner, B.D. Esry, H. Frostig, O. Heber, A. Natan, V.S. Prabhudesai, D. Schwalm, Y. Silberberg, D. Strasser, I.D. Williams, D. Zajfman
J. Phys. B. 48 (20), 201001 (2015)
Probing electron delays in above threshold ionization
L. J. Zipp, A. Natan, and P. H. Bucksbaum
Optica, 1 (6), 361-364 (2014)
Delayed Delayed Ultrafast X-ray Auger Probing (DUXAP) of Nucleobase Ultraviolet Photoprotection
B. McFarland, J. Farrell, N. Berrah, C. Bostedt, J. Bozek, P. H. Bucksbaum, R. Coffee, J. Cryan, L. Fang, R. Feifel, K. Gaffney, J. M. Glownia, T. Martinez, M. Mucke, B. Murphy, S. Miyabe, A. Natan, T. Osipov, V. Petrovic, S. Schorb, T. Schultz, L. Spector, F. Tarantelli, I. Tenney, S. Wang, W. White, J. White, and M. Guehr
Nature Communications 5 (2014)
Quantum control of photodissociation by manipulation of bond softening
A. Natan, V. S. Prabhudesai, U. Lev, B. D. Bruner, D. Strasser, D. Schwalm, I. Ben-Itzhak, O. Heber, D. Zajfman, and Y. Silberberg
Phys. Rev. A. 86, 043418 (2012)
Standoff detection via single-beam spectral notch filtered pulses
A. Natan, J. M. Levitt, L. Graham, O. Katz, and Y. Silberberg.
Appl. Phys. Lett. 100, 051111 (2012)
Effect of Linear Chirp on Strong Field Photodissociation of H2+
V. S. Prabhudesai, A. Natan, B. D. Bruner, Y. Silberberg, U. Lev, O. Heber, D. Strasser, D. Schwalm, D. Zajfman, I. Ben-Itzhak.
J. Korean Phys. Soc. 59 , 2890 (2011)
Single-pulse stimulated Raman scattering spectroscopy
H. Frostig, O. Katz, A. Natan, and Y. Silberberg.
Optics Letters, 36 (7), 1248 (2011)
Tracing the photodissociation probability of H2+ in intense fields using chirped laser pulses
V. S. Prabhudesai, U. Lev, A. Natan, B. D. Bruner, A. Diner, O. Heber, D. Strasser, D. Schwalm, I. Ben-Itzhak, J. J. Hua, B. D. Esry, Y. Silberberg, and D. Zajfman
Phys. Rev. A 81 023401 (2010)
Quantum state measurements using multipixel photon detectors
I. Afek, A. Natan, O. Ambar, and Y. Silberberg
Phys. Rev. A 79, 043830 (2009)
Shaped Femtosecond Pulses for Remote Chemical Detection
O. Katz, A. Natan, S. Rosenwaks, and Y. Silberberg
Opt. Phot. News 47 , Dec (2008)
Standoff detection of trace amounts of solids by nonlinear Raman spectroscopy using shaped femtosecond pulses
O. Katz, A. Natan, Y. Silberberg, and S. Rosenwaks
Appl. Phys. Lett. 92, 171116 (2008)
Spatio-temporal coherent control of atomic systems: weak to strong field transition and breaking of symmetry in 2D maps
H. Suchowski, A. Natan, B.D Bruner and Y. Silberberg
J. Phys. B. 41 074008 (2008)

 

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Codes

"A man must have a code." (Bunk Moreland)

GitHub | Matlab File Exchange

2D Fast Peak Finder The aim was to be faster than more sophisticated techniques yet good enough to find peaks in noisy data. The code analyzes noisy 2D images and find peaks using robust local maxima finder (1 pixel resolution) or by weighted centroids (sub-pixel resolution). The code is designed to be as fast as possible, so I kept it pretty basic. It best works when using uint16 or uint8 images, and assumes that peaks are relatively sparse. download.


Polar Onion Peeling (POP) is a fast method that combines onion peeling in the radial axis with Legedre decomposition in the angle axis, to deconvolve raw velocity map imaging data. The code implements the method shown at Rev. Sci. Instr. 80, 053104 (2009). It supports images of up to 4K resolution and accepts arbitrary (even) beta parameters. Specific quadrants of the image can be selected in the analysis in case of image asymmetries. download.


Beam propagation This code simulates the focusing of spherical Gaussian beams using a series of thin lenses (Based on Applied Optics, Vol. 22, Issue 5, pp. 658-661 (1983). download.


Dark Mode Plot Transform your MATLAB plots to fit dark mode theme backgrounds! The function test which of the figure colors are not suitable to be used over a dark background (via color contrast), and adjust colors accordingly using a desaturation and brightness approach. download.


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