Dr. Philip Johnson

Photo of Philip Johnson
Paul Scherrer Institute PSI
Forschungsstrasse 111
5232 Villigen PSI


Philip J. M. Johnson completed his Ph.D. at the University of Toronto in 2013 under Prof. R. J. Dwayne Miller, having studied the ultrafast isomerization reactions of bacterial and mammalian rhodopsins using time-resolved electronic spectroscopies. He then moved to the University of Zurich for a postdoc in the group of Prof. Peter Hamm, using mid-infrared spectroscopy of genetically-encoded vibrational probes to study protein structure and dynamics during ligand binding. Since 2018, Philip is a member of the experimental laser group in the Laboratory for Nonlinear Optics at PSI.

Institutional Responsibilities

Philip is closely affiliated with the Alvra endstation at SwissFEL, providing the light to excite photochemical and photobiological processes under study with x-ray diffraction and/or spectroscopy methods at Alvra. He is also involved in the development of laser/x-ray arrival time instrumentation, and new ultrafast pulsed laser sources and their characterization.

Scientific Research

Philip is interested in the role played by vibrational dynamics in directing ultrafast chemical reactions initiated by light. The interplay between vibrational and electronic degrees of freedom leads to the ultrafast chemistry that underlies such diverse biological processes as our sense of vision to the initial steps in photosynthesis in some bacteria and plants. Philip's goal is to realize the temporal resolution and sensitivity necessary to observe these coherent molecular motions in the primary photochemistry of biological systems at Alvra.

Selected Publications

For an extensive overview we kindly refer you to the publication repositories DORA, ORCiD, and Google Scholar.

Femtosecond-to-millisecond structural changes in a light-driven sodium pump, Petr Skopintsev, David Ehrenberg, Tobias Weinert, Daniel James, Rajiv K. Kar, Philip J. M. Johnson, Dmitry Ozerov, Antonia Furrer, Isabelle Martiel, Florian Dworkowski, Karol Nass, Gregor Knopp, Claudio Cirelli, Christopher Arrell, Dardan Gashi, Sandra Mous, Maximilian Wranik, Thomas Gruhl, Demet Kekilli, Steffen Brünle, Xavier Deupi, Gebhard F. X. Schertler, Roger M. Benoit, Valerie Paneels, Przemyslaw Nogly, Igor Schapiro, Christopher Milne, Joachim Heberle, & Jörg Standfuss, Nature, 20 May 2020

Excited-State Vibronic Dynamics of Bacteriorhodopsin from Two-Dimensional Electronic Photon Echo Spectroscopy and Multiconfigurational Quantum Chemistry, Samer Gozem, Philip J. M. Johnson, Alexei Halpin, Hoi Ling Luk, Takefumi Morizumi, Valentyn I. Prokhorenko, Oliver P. Ernst, Massimo Olivucci, & R. J. Dwayne Miller, J. Phys. Chem. Lett. 2020, 11, 10, 3889–3896 https://doi.org/10.1021/acs.jpclett.0c01063

Optical second harmonic generation in LiB3O5modulated by intense femtosecond X-ray pulses, Yunpei Deng, Serhane Zerdane, Xinhua Xie, Edwin Divall, Philip J. M. Johnson, Christopher Arrell, Henrik Till Lemke, Roman Mankowsky, Alex Oggenfuss, Cristian Svetina, Christian Erny, Claudio Cirelli, Christopher Milne, Gregor Knopp, Paul Beaud, & Steven L. Johnson, Op. Express Vol. 28 pp. 11117-11127 (2020)