1. Juan J. Carrera, Sang-Kil Son, and Shih-I Chu, “Ab initio theoretical investigation of the frequency comb structure and coherence in the vuv-xuv regimes via high-order harmonic generation,” Phys. Rev. A 77, 031401(R) (2008).
2. Sang-Kil Son and Shih-I Chu, “Many-mode Floquet theoretical approach for coherent control of multiphoton dynamics driven by intense frequency-comb laser fields,” Phys. Rev. A 77, 063406 (2008).
3. Sang-Kil Son, Siyuan Han, and Shih-I Chu, “Floquet formulation for the investigation of multiphoton quantum interference in a superconducting qubit driven by a strong ac field,” Phys. Rev. A 79, 032301 (2009).
4. Sang-Kil Son and Shih-I Chu, “Multielectron effects on the orientation dependence and photoelectron angular distribution of multiphoton ionization of CO₂ in strong laser fields,” Phys. Rev. A 80, 011403(R) (2009).
5. Sang-Kil Son, Dmitry A. Telnov, and Shih-I Chu, “Probing the origin of elliptical high-order harmonic generation from aligned molecules in linearly polarized laser fields,” Phys. Rev. A 82, 043829 (2010).
6. Sang-Kil Son, Linda Young, and Robin Santra, “Impact of hollow-atom formation on coherent x-ray scattering at high intensity,” Phys. Rev. A 83, 033402 (2011).
7. R. W. Dunford, S. H. Southworth, D. Ray, E. P. Kanter, B. Krässig, L. Young, D. A. Arms, E. M. Dufresne, D. A. Walko, O. Vendrell, Sang-Kil Son, and R. Santra, “Evidence for interatomic Coulombic decay in Xe K-shell-vacancy decay of XeF₂,” Phys. Rev. A 86, 033401 (2012).
8. Sang-Kil Son and Robin Santra, “Monte Carlo calculation of ion, electron, and photon spectra of xenon atoms in x-ray free-electron laser pulses,” Phys. Rev. A 85, 063415 (2012).
9. Arina Sytcheva, Stefan Pabst, Sang-Kil Son, and Robin Santra, “Enhanced nonlinear response of Ne⁸⁺ to intense ultrafast x rays,” Phys. Rev. A 85, 023414 (2012).
10. Robert Thiele, Sang-Kil Son, Beata Ziaja, and Robin Santra, “Effect of screening by external charges on the atomic orbitals and photoinduced processes within the Hartree-Fock-Slater atom,” Phys. Rev. A 86, 033411 (2012).
11. Siddharth Bhardwaj, Sang-Kil Son, Kyung-Han Hong, Chien-Jen Lai, Franz X. Kärtner, and Robin Santra, “Recombination-amplitude calculations of noble gases, in both length and acceleration forms, beyond the strong-field approximation,” Phys. Rev. A 88, 053405 (2013).
12. Benedikt Rudek, Daniel Rolles, Sang-Kil Son, Lutz Foucar, Benjamin Erk, Sascha Epp, Rebecca Boll, Denis Anielski, Christoph Bostedt, Sebastian Schorb, Ryan Coffee, John Bozek, Sebastian Trippel, Tatiana Marchenko, Marc Simon, Lauge Christensen, Sankar De, Shin-ichi Wada, Kiyoshi Ueda, Ilme Schlichting, Robin Santra, Joachim Ullrich, and Artem Rudenko, “Resonance-enhanced multiple ionization of krypton at an x-ray free-electron laser,” Phys. Rev. A 87, 023413 (2013).
13. Ludger Inhester, Kota Hanasaki, Yajiang Hao, Sang-Kil Son, and Robin Santra, “X-ray multiphoton ionization dynamics of a water molecule irradiated by an x-ray free-electron laser pulse,” Phys. Rev. A 94, 023422 (2016).
14. Koudai Toyota, Sang-Kil Son, and Robin Santra, “Interplay between relativistic energy corrections and resonant excitations in x-ray multiphoton ionization dynamics of Xe atoms,” Phys. Rev. A 95, 043412 (2017).
15. John Jasper Bekx, Sang-Kil Son, Robin Santra, and Beata Ziaja, “Ab initio calculation of electron-impact-ionization cross sections for ions in exotic electron configurations,” Phys. Rev. A 98, 022701 (2018).
16. Julia M. Schäfer, Ludger Inhester, Sang-Kil Son, Reinhold F. Fink, and Robin Santra, “Electron and fluorescence spectra of a water molecule irradiated by an x-ray free-electron laser pulse,” Phys. Rev. A 97, 053415 (2018).
17. Yajiang Hao, Ludger Inhester, Sang-Kil Son, and Robin Santra, “Theoretical evidence for the sensitivity to molecular size of charge-rearrangement-enhanced x-ray ionization,” Phys. Rev. A 100, 013402 (2019).
18. Yoshiaki Kumagai, Zoltan Jurek, Weiqing Xu, Hironobu Fukuzawa, Koji Motomura, Denys Iablonskyi, Kiyonobu Nagaya, Shin-ichi Wada, Subhendu Mondal, Tetsuya Tachibana, Yuta Ito, Tsukasa Sakai, Kenji Matsunami, Toshiyuki Nishiyama, Takayuki Umemoto, Christophe Nicolas, Catalin Miron, Tadashi Togashi, Kanade Ogawa, Shigeki Owada, Kensuke Tono, Makina Yabashi, Sang-Kil Son, Beata Ziaja, Robin Santra, and Kiyoshi Ueda, “Real-time observation of disintegration processes within argon clusters ionized by a hard-x-ray pulse of moderate fluence,” Phys. Rev. A 101, 023412 (2020).
19. Daria Kolbasova, Maximilian Hartmann, Rui Jin, Alexander Blättermann, Christian Ott, Sang-Kil Son, Thomas Pfeifer, and Robin Santra, “Probing ultrafast coherent dynamics in core-excited xenon by using attosecond XUV-NIR transient absorption spectroscopy,” Phys. Rev. A 103, 043102 (2021).
20. Laura Budewig, Sang-Kil Son, and Robin Santra, “Theoretical investigation of orbital alignment of x-ray-ionized atoms in exotic electronic configurations,” Phys. Rev. A 105, 033111 (2022).
21. Stanislaw Wirok-Stoletow, Rui Jin, Daria Kolbasova, Sang-Kil Son, Andrew Aquila, and Robin Santra, “Nonsequential two-photon absorption in solid Ge irradiated by an intense x-ray free-electron-laser pulse,” Phys. Rev. A 106, 023118 (2022).
22. Laura Budewig, Sang-Kil Son, and Robin Santra, “State-resolved ionization dynamics of neon atom induced by x-ray free-electron-laser pulses,” Phys. Rev. A 107, 013102 (2023).