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Education & Training

2000-2004 Postdoctoral Scholar, California Institute of Technology, Pasadena, California (advisor: Ahmed H. Zewail)
2000 Ph.D. Physics, University of Texas, Austin, Texas (advisor: Manfred Fink)
1990 B.Sc. Physics, National Taiwan Normal University, Taipei, Taiwan

Academic Positions

2015   Professor, Michigan State University, East Lansing, Michigan 
2010   Associate Professor, Michigan State University, East Lansing, Michigan
2004   Assistant Professor, Michigan State University, East Lansing, Michigan 



2005 Sidhu Award
2009 Outstanding Young Researcher Award from OCPA


  • RF-enabled ultrafast electron microscope, US20140346355 . 2015 May 05.
  • Ultrafast angle-resolved electron energy loss spectroscopy, USA 10607807. 2020 March 31.



  • X. Sun, S. Sun, and C.-Y. Ruan. (Review) Toward nonthermal control of excited quantum materials: Framework and investigations by ultrafast electron scattering and imaging, Comptes Rendus. Physique, Online first (2021), pp. 1-59 (2021).

  • C.-Y. Ruan, (Commentary) Hidden in plain light, Nature Physics 17, 884 (2021).

  • F. Zhou, J. Williams, S. Sun, S.D. Malliakas, M.G. Kanatzidi, A.F. Kemper, C.-Y. Ruan. Nonequilibrium dynamics of spontaneous symmetry breaking into a hidden state of charge-density wave. Nature communications 12, 566 (2021); DOI: 10.1038/s41467-020-20834-5. 

  • S. Sun, X. Sun, D. Bartles, E. Wozniak, J. Williams, P. Zhang, C.-Y. Ruan. Direct imaging of plasma waves using ultrafast electron microscopy. Structural Dynamics 7, 064301 (2020). 

  • Sun, S.; Sun, X.; Williams, J.; Ruan, C.-Y. Development of RF-compressed high-throughput femtosecond electron microscope, Microscopy and Microanalysis 26, 1-4 (2020).

  • B.S. Zerbe, X. Xiang, C.Y. Ruan, S.M. Lund, P.M. Duxbury. Dynamical bunching and density peaks in expanding Coulomb clouds. Phys. Rev. Accel. Beams 21, 064201 (2018).

  • J. Williams, F. Zhou, T. Sun, Z. Tao, K. Chang, K. Makino, M. Berz, P.M. Duxbury, and C.-Y. Ruan, Active control of bright electron beams with RF optics for femtosecond microscopy, Struc. Dyn. 4 (A tribute to Ahmed Zewail), 044035 (2017).

  • F. Zhou, J. Williams, C.-Y. Ruan, Femtosecond electron spectroscopy in an electron microscope with high-brightness beams, Chem. Phys. Lett. 683 (Ahmed Zewail Commemoration Issue), 488 (2017).
  • C.-Y. Ruan, (Perspective) Molecular imaging at 1-femtosecond resolution, Science 354, 283-284 (2016).
  • Z. Tao, F. Zhou, T.–R. T. Han, D. Torres, T. Wang, N. Sepulveda, K. Chang, M. Young R. R. Lunt, C.-Y. Ruan, The nature of photoinduced phase transition and metastable states in vanadium dioxide, Scientific Reports 6, 38514 (2016).
  • T-R.T. Han, F. Zhou, C.D. Malliakas, P.M. Duxbury, S.D. Mahanti, M.G. Kanatzidis, and C-Y. Ruan, Exploration of metastability and hidden phases in correlated electron crystals visualized by femtosecond optical doping and electron crystallography, Science Advances 1, e1400173 (2015).
  • H. Zhang, J. Portman, Z. Tao, P.M. Duxbury, C.-Y. Ruan, K. Makino, and M. Berz, The Differential Algebra Based Multiple Level Fast Multipole Algorithm for 3D Space Charge Field Calculation and Photoemission Simulation, Micros. Microana., 21 (S4), 224 (2015).
  • J. Portman, H. Zhang, K. Makino, C.-Y. Ruan, M. Berz, P. M. Duxbury, Multiscale Modeling of the Ultrafast electron microscope: From the photocathode to the sample, Adv. Imag. Elect. Phys., 191, 117 (2015).
  • H. Zhang, Z. Tao, C.-Y. Ruan, M. Berz, Differential algebra based multiple level fast multipole algorithm, Adv. Imag. Elect. Phys., 191, 56 (2015).
  • J. Portman, H. Zhang, K. Makino, C. Y. Ruan, M. Berz, and P. M. Duxbury, Untangling the contributions of image charge and laser profile for optimal photoemission of high-brightness electron beams, J. Appl. Phys. 116, 174302 (2014).
  • C.-Y. Ruan, P. M. Duxbury, M. Berz, The perspectives of femtosecond imaging and spectroscopy of complex materials using electrons. Z. Liu, I. C. Khoo, Eds., Ultrafast Nonlinear Imaging and Spectroscopy II, Proc. of SPIE, vol. 9198 (2014).
  • K. Chang, R.A. Murdick, T.-R.T. Han, F. Yuan, and C.-Y. Ruan, Light-induced charge carrier dynamics at nanostructured interfaces investigated by ultrafast electron diffractive photovoltammetry, Eds. J. Wu and Z.M. Wang, Springer Book Series on Quantum Dot Solar Cell (2014).
  • J. Portman, H. Zhang, Z. Tao, K. Makino, M. Berz, P.M. Duxbury, and C.-Y. Ruan, Computational and experimental characterizations of high-brightness beams for femtosecond electron imaging and spectroscopy, Appl. Phys. Lett. 103, 253115 (2013).
  • Z. Tao, T.-R. T. Han, C.-Y. Ruan, Anisotropic electron-phonon coupling investigated by ultrafast electron crystallography: Three-temperature model, Phys. Rev. B 87, 235124 (2013).
  • Z. Tao, T.-R. T. Han, S. D. Mahanti, P. M. Duxbury, F. Yuan, C.-Y. Ruan, K. Wang, J. Wu, Decoupling of Structural and Electronic Phase Transitions in VO2, Phys. Rev. Lett. 109, 166406 (2012).
  • T.-R. T. Han, Z. Tao, S.D. Mahanti, K. Chang, C.-Y.  Ruan, C. D. Malliakas, M. G. Kanatzidis, Structural dynamics of two-dimensional charge-density waves in CeTe3 investigated by ultrafast electron crystallography, Phys. Rev. B 86, 075145 (2012).
  • Z. Tao, H. Zhang, P.M. Duxbury, M. Berz, C.-Y. Ruan, Space-charge effects in ultrafat electron diffraction and imaging, J. Appl. Phys. 111, 044316 (2012). 
  • C.-Y. Ruan, Four-dimensional electron nanocrystallography, Research in Optical Sciences, OSA Technical Digest (Optical Society of America, 2012), paper IT3D.5.
  • K. Chang, R.A. Murdick, Z. Tao, T.-R. T. Han, C.-Y. Ruan, Ultrafast electron diffractive voltammetry: General formalism and applications,  Mod. Phys. Lett. B 25, 2099 (2011). (Review)
  • C.L. Farrow, C-Y. Ruan, S.J.L. Billinge, Quantitative nanoparticle structures from electron crystallography data, Phys. Rev. B 81, 134104 (2010).
  • R. K. Raman, R. A. Murdick, R. J. Worhatch, Y. Murooka, S. D. Mahanti, T-R. T. Han, and C-Y. Ruan, Electronically Driven Fragmentation of Silver Nanocrystals Revealed by Ultrafast Electron Crystallography, Phys. Rev. Lett. 104, 123401 (2010). 
  • R.K. Raman, Z. Tao, T-R. Han, C-Y. Ruan, Ultrafast imaging of photoelectron packets generated from graphite surafce, Appl. Phys. Lett. 95, 181108 (2009).
  • C-Y. Ruan, Y. Murooka, R.K. Raman, R.A. Murdick, R. J. Worhatch, A. Pell, The development and applications of ultrafast electron nanocrystallography, Micros. Microanal. 15, 323 (2009). (Review) 
  • R.K. Raman, Y. Murooka, C-Y. Ruan, T. Yang, S. Berber, D. Tomanek, Direct observation of optically induced transient structures in graphite using ultrafast electron crystallography, Phys. Rev. Lett. 101, 077401 (2008).
  • R.A. Murdick, R.K. Raman, Y. Murooka, C.-Y. Ruan, Photovoltage dynamics of the hydroxylated Si(111) surface investigated by ultrafast electron diffraction, Phys. Rev. B 77, 245329 (2008).
  • C.-Y. Ruan, Y. Murooka, R.K. Raman, R.A. Murdick, Dynamics of size-Selected gold nanoparticles studied by ultrafast electron nanocrystallography, Nano Lett. 7, 1290 (2007).
  • C-Y. Ruan, Y. Murooka, R.K. Raman, R. Murdick, and M.A. Khasawneh, Towards ultrafast diffraction and spectroscopy of interfaces and nanomaterials using femtosecond focused electron pulses, Microscopy and Microanalysis 12 (Suppl.2), 150 (2006).
  • C.-Y. Ruan, S.-S. Yang, A.H. Zewail, Structures and dynamics of self-assembled surface monolayers observed by ultrafast electron crystallography", J. Am. Chem. Soc. 126, 12797 (2004).
  • C.-Y. Ruan, V.A. Lobastov, V. Franco, S. Chen, A.H. Zewail, Ultrafast electron crystallography of Interfacial Water, Science (304), 974 (2004).
  • V. Franco, S. Chen, C.-Y. Ruan, V.A. Lobastov, A.H. Zewail, Ultrafast electron crystallography of surface structural dynamics with atomic-scale resolution, Angewandte Chemie Intl. (43), 2705 (2004).
  • C.-Y. Ruan, V. Franco, V.A. Lobastov, S. Chen, A.H. Zewail, Ultrafast electron crystallography : transient structures of molecules, surfaces and phase transitions, Proc. Natl. Acad. Sci. U.S.A.  101, 1123 (2004).
  • B.M. Goodson, C.-Y. Ruan, V.A. Lobastov, R. Srinivasan, A.H. Zewail, Ultrafast electron diffraction: complex landscapes of molecular structures in thermal and light-mediated reactions, Chem. Phys. Lett. (374), 417 (2003).
  • R. Srinivasan, V.A. Lobastov, C.-Y. Ruan, A.H. Zewail, Ultrafast electron diffraction (UED) - A new development for the 4D determination of transient molecular structures, HELVETICA CHIMICA ACTA (86) 1763 (2003).
  • V.A. Lobastov, R. Srinivasan, F. Vigliotti, C.-Y. Ruan, J. Feenstra, S. Chen, S.T. Park, S. Xu, and A. H. Zewail, Ultrafast electron diffraction - From the gas phase to the condensed phase with picosecond and femtosecond resolution, Springer Series in Ultrafast Optics IV, Eds. F. Krausz, G. Korn, P. Corkum, and I. Walmsley, 413 (2003).
  • V.A. Lobastov, R. Srinivasan, B.M. Goodson, C.-Y. Ruan, J.S. Feenstra, A.H. Zewail, Ultrafast diffraction of transient molecular structures in radiationless transitions, J. Phys. Chem. A  105, 11159 (2001).
  • H. Ihee, V. A. Lobastov, U. Gomez, B. M. Goodson, R. Srinivasan, C.-Y. Ruan, A. H. Zewail, Direct Imaging of Transient Molecular Structures with Ultrafast Diffraction, Science (291), 458 (2001).
  • C.-Y. Ruan, V.A. Lobastov, R. Srinivasan, B.M. Goodson, H. Ihee, A.H. Zewail, Ultrafast diffraction and structural dynamics: The nature of complex molecules far from equilibrium, Proc. Natl. Acad. Sci. U.S.A. (98), 7117 (2001).
  • C.-Y. Ruan and M. Fink, Plasma-modulated fast electron pulsing and bunching, J. App. Phys. (89), 654 (2001).
  • V. Mastryukov, C.-Y. Ruan, and M. Fink, Zhiqiang Wang, and Ruth Pachter, Electron diffraction studies of metal phthalocyanines, MPc, where M = Ni and Cu, J. Mol. Struct. Sp. Iss. (556), 225 (2000).
  • C.-Y. Ruan, V. Mastryukov and M. Fink, Electron diffraction studies of metal Phthalocyanines, MPc, where M = Sn, Mg and Zn (reinvestigation), J. Chem. Phys. (11), 3035(1999).
  • C.-Y. Ruan, and M. Fink, Emission optics of the Steigerwald type electron gun, Rev. Sci. Instr. (70), 4207(1999).
  • C.-Y. Ruan, S. Nguyen, and M. Fink, Optimization of spherical analyzer with finite size effects, Rev. Sci. Instr. (70), 4213(1999).