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Personal Data

Karen Z. Hatsagortsyan

addressMax-Planck-Institut für Kernphysik (MPIK)
Max Planck Institute for Nuclear Physics
Saupfercheckweg 1
69117 Heidelberg
Germany
emailkaren.hatsagortsyanmpi-hd.mpgde
fax+ 49 (0)6221 516-152
phone+ 49 (0)6221 516-160
officeBO351
languages

Armenian - mother tongue,
Russian - fluent,
English - good,
German - fair.

Education History

1980-1983

Post-graduate study, Department of Theoretical Physics, Yerevan State University (Yerevan, Armenia)
Topic: "Combined mechanisms of free electron laser, classical bunching and quantum modulation of electron beam"
Advisor: Professor Dr. H. K. Avetissian

1973-1978

Graduated in Physics, Yerevan State University (Yerevan, Armenia). Specialization in theoretical physics.
Diploma thesis: "Formfactors of nucleons in the quark-gluon model"
Advisors: Dr. S. V. Esaybegyan and Professor Dr. S. G. Matinyan (Yerevan Institute of Physics)

Employment History

since 2004

Group Leader, Max Planck Institute for Nuclear Physics, Heidelberg, Germany

1991-2004

Senior Research Associate, Associate Professor, Department of Theoretical Physics, Yerevan State University (Yerevan, Armenia)
Since 1994 - Leading Research Associate in the Plasma Physics Laboratory

1987-1991

Research Associate, Plasma Physics Laboratory, Institute for Applied Problems of Physics, Academy of Science (Yerevan, Armenia)

1985-1987

Research Assistant, Department of General Physics, Yerevan State University (Yerevan, Armenia)

1984-1985

Research Assistant, Institute for Applied Problems of Physics, Academy of Science (Yerevan, Armenia)

Lecturing Experience

2006

A graduate course at Heidelberg University (shared with Dr. D. Bauer):
"Theory of intense laser-matter interaction"

1991-2001

Graduate courses at Yerevan State University: "Electrodynamics of Continuous Media", "Oscillations and Waves", "Nonlinear Physics", "Radiative Processes", "Plasma Physics", "Plasma Electronics"

Grants and Fellowships

2004

Max Planck Fellowship, Max Planck Institute for Nuclear Physics, Heidelberg, Germany, from July 2004 to June 2007

2003

Return Fellowship of the Alexander von Humboldt Foundation, Germany, from September 2003 to June 2004

2002

Georg Forster Fellowship of the Alexander von Humboldt Foundation, Germany, at Theoretische Quantendynamik, Freiburg University (Freiburg, Germany) from February 2, 2002 to May 31, 2003

1999

DAAD (German Foundation for Academic Exchange) grant for a Study Visit at the division Theoretische Quantendynamik, Freiburg University (Freiburg, Germany) from September 25 to November 25, 1998

1998

Travel Grant of the Open Society Institute for initiation of collaboration, spent at Theoretische Quantendynamik, Freiburg University (Freiburg, Germany) from October 10 to November 10, 1998

1993

Individual Grant of the International Science Foundation (Soros)

Refereeing Service

Physical Review Letters; Physical Review A, D, E; Physical Review ST Accel. Beams; Journal of Physics B, New Journal of Physics, Europhysics Letter, Nature Photonics, Light: Science & Applications (Nature Publ.), Optics Letters, Journal OSA B, Optics Express, Physics of Plasmas, Optics Communications, Physics Letters A, The European Physical Journal D, Canadian Journal of Physics.

Elsevier Outstanding Reviewer, 2015.
Outstanding Referee of the Physical Review and Physical Review Letters journals, 2016.

Since 2016 serves as an Editorial Board Member for the journal "Scientific Reports", Nature Publishing Group.

Research Interests

Strong field optical physics. Relativistic nonlinear optics: HHG and ATI in the relativistic regimes. High energy laser physics. Nonlinear QED effects in strong laser fields. Laser-driven collider. Radiation reaction effects in strong laser fields. Coulomb field focusing effects in strong field processes. Lowenergy structures at ATI. Strong field physics in XUV domain. Stimulated radiative processes with free electrons including nonlinear and multiphoton effects. Free electron lasers and free-free transitions. An earlier minor research interest was connected with the interaction of acoustic waves with low-temperature plasma.

Publications in MPIK

90 Polarized Positron Beams via Intense Two-Color Laser Pulses

Y. Chen, P. He, R. Shaisultanov, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 123, 174801 (2019)

89 Holographic interferences in strong-field ionization beyond the dipole approximation: The influence of the peak and focal-volume-averaged laser intensities

B. Willenberg, J. Maurer, U. Keller, J. Daněk, M. Klaiber, N. Teeny, K.Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 100, 033417 (2019)

88 Single-shot determination of spin-polarization for ultrarelativistic electron beams via nonlinear Compton scattering

Y. Li, R. Guo, R. Shaisultanov, K. Z. Hatsagortsyan, and J. Li
Physical Review Applied 12, 014047 (2019)

87 Imprint of the stochastic nature of photon emission by electrons on the proton energy spectra in the laser-plasma interaction

F. Wan, K. Xue, Z. Dou, K. Z. Hatsagortsyan, W. Yan, D. Khikhlukha, S. V Bulanov, G. Korn, Y. Zhao, Z. Xu, and J. Li
Plasma Physics and Controlled Fusion 61, 084010 (2019)

86 Semiclassical limitations for photon emission in strong external fields

E. Raicher, S. Eliezer, C. H. Keitel, and K. Z. Hatsagortsyan
Physical Review A 99, 052513 (2019)

85 Ultrarelativistic Electron-Beam Polarization in Single-Shot Interaction with an Ultraintense Laser Pulse

Y. Li, R. Shaisultanov, K. Z. Hatsagortsyan, F. Wan, C. H. Keitel, and J. Li
Physical Review Letters 122, 154801 (2019)

84 Generation of twisted γ-ray radiation by nonlinear Thomson scattering of twisted light

Y. Chen, K. Z. Hatsagortsyan, and C. H. Keitel
Matter and Radiation at Extremes 4, 024401 (2019)

83 Role of high ponderomotive energy in laser-induced nonsequential double ionization

T. Shaaran, N. Camus, J. Dura, L. Fechner, A. Thai, A. Britz, M. Baudisch, T. Steinle, A. Senftleben, C. D. Schröter, J. Ullrich, T. Pfeifer, C. H. Keitel, J. Biegert, K. Z. Hatsagortsyan, and R. Moshammer
Physical Review A 99, 023421 (2019)

82 Determining the carrier-envelope phase of relativistic laser pulses via electron-momentum distribution

Y. Li, J. Li, K. Z. Hatsagortsyan, Y. Zhao, B. Zhang, Y. Li, Y. Liu, Z. Zhang, Z. Xu, and C. H. Keitel
Physical Review A 99, 013850 (2019)

81 High-energy direct photoelectron spectroscopy in strong-field ionization

P. He, M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 98, 053428 (2018)

80 Electron-angular-distribution reshaping in the quantum radiation-dominated regime

Y. Li, Y. Zhao, K. Z. Hatsagortsyan, C. H. Keitel, and J. Li
Physical Review A 98, 052120 (2018)

79 γ-Ray Beams with Large Orbital Angular Momentum via Nonlinear Compton Scattering with Radiation Reaction

Y. Chen, J. Li, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 121, 074801 (2018)

78 Coulomb effect in laser-induced recollision excitation

T. Shaaran, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 98, 023410 (2018)

77 Analytical approach to Coulomb focusing in strong-field ionization. I. Nondipole effects

J. Daněk, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 97, 063409 (2018)

76 Analytical approach to Coulomb focusing in strong-field ionization. II. Multiple recollisions

J. Daněk, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 97, 063410 (2018)

75 Interplay between Coulomb-focusing and non-dipole effects in strong-field ionization with elliptical polarization

J. Daněk, M. Klaiber, K. Z. Hatsagortsyan, C. H. Keitel, B. Willenberg, J. Mauer, B. W. Mayer, C. R. Phillips, L. Gallmann, and U. Keller
Journal of Physics B: Atomic, Molecular and Optical Physics 51, 114001 (2018)

74 Single-Shot Carrier-Envelope Phase Determination of Long Superintense Laser Pulses

J. Li, Y. Chen, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 120, 124803 (2018)

73 Probing the ionization wave packet and recollision dynamics with an elliptically polarized strong laser field in the nondipole regime

J. Mauer, B. Willenberg, J. Daněk, B. W. Mayer, C. R. Phillips, L. Gallmann, M. Klaiber, K. Z. Hatsagortsyan, C. H. Keitel, and U. Keller
Physical Review A 97, 013404 (2018)

72 Under-the-Tunneling-Barrier Recollisions in Strong-Field Ionization

M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 120, 013201 (2018)

71 Experimental Evidence for Quantum Tunneling Time

N. Camus, E. Yakaboylu, L. Fechner, M. Klaiber, M. Laux, Y. Mi, K. Z. Hatsagortsyan, T. Pfeifer, C. H. Keitel, and R. Moshammer
Physical Review Letters 119, 023201 (2017)

70 Limits of Strong Field Rescattering in the Relativistic Regime

M. Klaiber, K. Z. Hatsagortsyan, J. Wu, S. S. Luo, P. Grugan, and B. C. Walker
Physical Review Letters 118, 093001 (2017)

69 Strong-field ionization via a high-order Coulomb-corrected strong-field approximation

M. Klaiber, J. Daněk, E. Yakaboylu, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 95, 023403 (2017)

68 Angle-resolved stochastic photon emission in the quantum radiation-dominated regime

J. Li, Y. Chen, K. Z. Hatsagortsyan, and C. H. Keitel
Scientific Reports 7, 11556 (2017)

67 Fields of an ultrashort tightly focused laser pulse

J. Li, Y. Salamin, K. Z. Hatsagortsyan, and C. H. Keitel
Journal of the Optical Society of America B-Optical Physics 33, 405-411 (2016)

66 Attosecond Gamma-Ray Pulses via Nonlinear Compton Scattering in the Radiation-Dominated Regime

J. Li, K. Z. Hatsagortsyan, B. J. Galow, and C. H. Keitel
Physical Review Letters 115, 204801 (2015)

65 Momentum partition between constituents of exotic atoms during laser-induced tunneling ionization

D. Cricchio, E. Fiordilino, and K. Z. Hatsagortsyan
Physical Review A 92, 023408 (2015)

64 Above-threshold ionization with highly charged ions in super-strong laser fields: III. Spin effects and its dependence on laser polarization

E. Yakaboylu, M. Klaiber, and K. Z. Hatsagortsyan
Physical Review A 91, 063407 (2015)

63 High-Energy Recollision Processes of Laser-Generated Electron-Positron Pairs

S. Meuren, K. Z. Hatsagortsyan, C. H. Keitel, and A. Di Piazza
Physical Review Letters 114, 143201 (2015)

62 Tunneling Dynamics in Multiphoton Ionization and Attoclock Calibration

M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 114, 083001 (2015)

61 Polarization-operator approach to pair creation in short laser pulses

S. Meuren, K. Z. Hatsagortsyan, C. H. Keitel, and A. Di Piazza
Physical Review D 91, 013009 (2015)

60 Spin-asymmetric laser-driven relativistic tunneling from ρ states

M. Klaiber and K. Z. Hatsagortsyan
Physical Review A: Atomic, Molecular, and Optical Physics 90, 063416 (2014)

59 The Wigner time delay for laser induced tunnel-ionization via the electron propagator

E. Yakaboylu, M. Klaiber, and K. Z. Hatsagortsyan
Physical Review A 90, 012116 (2014)

58 Robust Signatures of Quantum Radiation Reaction in Focused Ultrashort Laser Pulses

J. Li, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 113, 044801 (2014)

57 Spin dynamics in relativistic ionization with highly charged ions in super-strong laser fields

M. Klaiber, E. Yakaboylu, C. Müller, H. Bauke, G. G. Paulus, and K. Z. Hatsagortsyan
Journal of Physics B 47, 065603 (2014)

56 Quasiclassical propagator of a relativistic particle via the path-dependent gauge potential

E. Yakaboylu, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 89, 032115 (2014)

55 Relativistic features and time delay of laser-induced tunnel-ionization

E. Yakaboylu, M. Klaiber, H. Bauke, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 88, 063421 (2013)

54 Attosecond pulses at kiloelectronvolt photon energies from high-order-harmonic generation with core electrons

C. Buth, F. He, J. H. Ullrich, C. H. Keitel, and K. Z. Hatsagortsyan
Physical Review A 88, 033848 (2013)

53 Under-the-barrier dynamics in laser-induced relativistic tunneling

M. Klaiber, E. Yakaboylu, H. Bauke, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 110, 153004, 1-5 (2013)

52 Above-threshold ionization with highly charged ions in superstrong laser fields. II. Relativistic Coulomb-corrected strong-field approximation

M. Klaiber, E. Yakaboylu, and K. Z. Hatsagortsyan
Physical Review A 87, 023418, 1-11 (2013)

51 Above-threshold ionization with highly charged ions in superstrong laser fields. I. Coulomb-corrected strong-field approximation

M. Klaiber, E. Yakaboylu, and K. Z. Hatsagortsyan
Physical Review A 87, 023417, 1-8 (2013)

50 Enhancing the high-order harmonic generation yield within a specified spectral window via electron wave-packet engineering

M. C. Kohler and K. Z. Hatsagortsyan
Journal of the Optical Society of America B-Optical Physics 30, 57-61 (2012)

49 Extremely high-intensity laser interactions with fundamental quantum systems

A. Di Piazza, C. Müller, K. Z. Hatsagortsyan, and C. H. Keitel
Reviews of Modern Physics 84, 1177-1228 (2012)

48 Optimization of the recollision step in high-order harmonic generation

M. Klaiber, M. C. Kohler, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 85, 063829, 1-8 (2012)

47 Manipulating the Annihilation Dynamics of Positronium via Collective Radiation

N. Cui, M. Macovei, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 108, 243401, 1-5 (2012)

46 Coulomb focusing in above-threshold ionization in elliptically polarized midinfrared strong laser fields

C. Liu and K. Z. Hatsagortsyan
Physical Review. A 85, 023413, 1-10 (2012)

45 Macroscopic aspects of relativistic x-ray-assisted high-order-harmonic generation

M. Kohler and K. Z. Hatsagortsyan
Physical Review. A 85, 023819, 1-11 (2012)

44 Coherent x-ray generation from below-threshold harmonics

J. Liu, M. C. Kohler, C. H. Keitel, and K. Z. Hatsagortsyan
Physical Review A 84, 063817 (2011)

43 Scattering of intense laser radiation by a single-electron wave packet

J. P. Corson, J. Peatross, C. Müller, and K. Z. Hatsagortsyan
Physical Review. A 84, 053831 (2011)

42 Bragg Scattering of Light in Vacuum Structured by Strong Periodic Fields

G. Y. Kryuchkyan and K. Z. Hatsagortsyan
Physical Review Letters 104, 053604 (2011)

41 Time analysis of above-threshold ionization in extreme-ultraviolet laser pulses

H. Ebadi, C. H. Keitel, and K. Z. Hatsagortsyan
Physical Review. A 83, 063418 (2011)

40 Streaking at high energies with electrons and positrons

A. Ipp, J. Evers, C. H. Keitel, and K. Z. Hatsagortsyan
Physics Letters B 702, 383-387 (2011)

39 Wavelength and intensity dependence of multiple forward scattering of electrons at above-threshold ionization in mid-infrared strong laser fields

C. Liu and K. Z. Hatsagortsyan
Journal of Physics B: Atomic, Molecular and Optical Physics 44, 095402 (2011)

38 Phase-matched coherent hard X-rays from relativistic high-order harmonic generation

M. Kohler, M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Europhysics letters 94, 14002 (2011)

37 Attochirp-free High-order Harmonic Generation

M. C. Kohler, C. H. Keitel, and K. Z. Hatsagortsyan
Optics Express 19, 4411-4420 (2011)

36 Quantum Radiation Reaction Effects in Multiphoton Compton Scattering

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 105, 220403, 1-4 (2010)

35 Origin of Unexpected Low Energy Structure in Photoelectron Spectra Induced by Midinfrared Strong Laser Fields

C. P. Liu and K. Z. Hatsagortsyan
Physical Review Letters 105, 113003 (2010)

34 Laser-guided relativistic quantum dynamics

C. Liu, M. C. Kohler, K. Z. Hatsagortsyan, C. Müller, and C. H. Keitel
New Journal of Physics 11, 105045 (2009)

33 Exotic atoms in superintense laser fields : applications in atomic, nuclear, and particle physics

C. Müller, A. Shahbaz, T. J. Bürvenich, K. Z. Hatsagortsyan, and C. H. Keitel
European Physical Journal - Special Topics 175, 187-190 (2009)

32 Relativistic nonperturbative above-threshold phenomena in strong laser fields

C. Müller, K. Z. Hatsagortsyan, M. Ruf, S. J. Müller, H. G. Hetzheim, M. C. Kohler, and C. H. Keitel
Laser Physics 19, 1743-1752 (2009)

31 QED vacuum effects in intense laser fields

A. Di Piazza and K. Z. Hatsagortsyan
European Physical Journal - Special Topics 175, 181-185 (2009)

30 Strong Signatures of Radiation Reaction below the Radiation-Dominated Regime

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 102, 254802 (2009)

29 Lepton pair production in high-frequency laser fields

C. Müller, C. Deneke, M. Ruf, G. R. Mocken, K. Z. Hatsagortsyan, and C. H. Keitel
Laser Physics 19, 791-796 (2009)

28 Pair Production in Laser Fields Oscillating in Space and Time

M. Ruf, G. R. Mocken, C. Müller, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 102, 080402 (2009)

27 Laser photon merging in proton laser collisions

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review. A 78, 062109 (2008)

26 Quantum vacuum effects in strong laser beams

A. Di Piazza and K. Z. Hatsagortsyan
Plasma Physics and Controlled Fusion 50, 124035 (2008)

25 Muon pair creation from positronium in a linearly polarized laser field

C. Müller, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 78, 033408, 1-19 (2008)

24 Quantum interaction among intense laser beams in vacuum

A. Di Piazza and K. Z. Hatsagortsyan
European Physical Journal-Special Topics 160, 147-155 (2008)

23 Laser-driven relativistic recollisions

K. Z. Hatsagortsyan, M. Klaiber, C. Müller, M. C. Kohler, and C. H. Keitel
Journal of the Optical Society of America B-Optical Physics 25, B92-B103 (2008)

22 Photoemission of a single-electron wave packet in a strong laser field

J. Peatross, C. Müller, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 100, 153601, 1-4 (2008)

21 High-energy, nuclear and QED processes in strong laser fields

C. Müller, A. Di Piazza, A. Shahbaz, T. J. Bürvenich, J. Evers, K. Z. Hatsagortsyan, and C. H. Keitel
Laser Physics 18, 175-184 (2008)

20 Coherent hard x rays from attosecond pulse train-assisted harmonic generation

M. Klaiber, K. Z. Hatsagortsyan, C. Müller, and C. H. Keitel
Optics Letters 33, 411-413 (2008)

19 Particle physics with a laser-driven positronium atom

C. Müller, K. Z. Hatsagortsyan, and C. H. Keitel
Physics Letters B 659, 209-213 (2008)

18 Nonperturbative vacuum-polarization effects in proton-laser collisions

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 100, 010403 (2008)

17 Fully relativistic laser-induced ionization and recollision processes

M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 75, 063413 (2007)

16 Nonlinear interaction of strong laser fields in vacuum

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Laser Physics 17, 345-349 (2007)

15 Enhancement of vacuum polarization effects in a plasma

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Physics of Plasma 14, 032102 (2007)

14 Relativistic ionization rescattering with tailored laser pulses

M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 74, 051803, 1-4 (2006)

13 Muon pair creation from positronium in a circularly polarized laser field

C. Müller, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review D 74, 074017, 1-16 (2006)

12 Microscopic laser-driven high-energy colliders

K. Z. Hatsagortsyan, C. Müller, and C. H. Keitel
Europhysics Letters 76, 29-35 (2006)

11 Light Diffraction by a Strong Standing Electromagnetic Wave

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 97, 083603, 1-4 (2006)

10 Polarization-operator approach to electron-positron pair production in combined laser and Coulomb fields

A. I. Milstein, C. Müller, K. Z. Hatsagortsyan, U. D. Jentschura, and C. H. Keitel
Physical Review A 73, 062106 (2006)

9 Gauge-invariant relativistic strong-field approximation

M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 73, 053411 (2006)

8 Relativistic high-power laser–matter interactions

Y. I. Salamin, S. X. Hu, K. Z. Hatsagortsyan, and C. H. Keitel
Physics Reports 427, 41-155 (2006)

7 Harmonic generation from laser-driven vacuum

A. Di Piazza, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review D 72, 085005, 1-23 (2005)

6 Thin crystal layers in superstrong laser fields: Dynamics and coherent x-ray generation

K. Z. Hatsagortsyan and C. H. Keitel
Physical Review A 72, 023812, 1-15 (2005)

5 Above-threshold ionization beyond the dipole approximation

M. Klaiber, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review A 71, 033408, 1-7 (2005)

4 Positronium in Intense Laser Fields

B. Henrich, K. Z. Hatsagortsyan, and C. H. Keitel
Physical Review Letters 93, 013601 (2004)

3 Phase-matched high-harmonic generation from laser-driven crystals

K. Z. Hatsagortsyan and C. H. Keitel
Journal of Physics B: Atomic, Molecular and Optical Physics 35, L175-L180 (2002)

2 Spin and radiation in intense laser fields

M. Walser, D. J. Urbach, K. Z. Hatsagortsyan, S. Hu, and C. H. Keitel
Physical Review. A 65, 043410 (2002)

1 X-Ray Amplification by Laser Controlled Coherent Bremsstrahlung

K. Z. Hatsagortsyan and C. H. Keitel
Physical Review Letters 86, 2277-2280 (2001)