The recent research in the Johnson group has been on multiscale computations, theoretical chemistry and surface-enhanced spectroscopies such as Raman scattering (SERS), fluorescence (SEF) and Raman optical activity (SEROA). A stint at the NSF covered the broader areas of nanochemistry and chemical theory. Johnson's current interests include improving wavelet basis techniques for describing local fields surrounding plasmonic nanoparticles, dimerization reactions for ligands attached to these nanoparticles, and formation of conducting chains of single-walled carbon nanotubes due to RF electric field radiated from a Tesla coil (Teslaphoresis). The forces in chain formation are not completely understood, and electromagnetic simulations are being implemented to investigate them.
Johnson received his Ph. D. in Chemistry in 1981 at the University of Wisconsin, studying under theoretical chemist Joseph Hirschfelder. He then held a postdoctoral fellowship in theory with William Reinhardt at the University of Colorado and the University of Pennsylvania (large-amplitude molecular vibrations), and another postdoctoral fellowship in the experimental group of James Kinsey at the Massachusetts Institute of Technology (Raman spectroscopy of photodissociating molecules). He moved with Kinsey to Rice University in 1988 as a Senior Research Scientist and was appointed as a Faculty Fellow in the Department of Chemistry in 1994, followed by promotions to Senior Faculty Fellow in 2000 and Distinguished Faculty Fellow in 2004 (renamed Research Professor in 2017). He became an early collaborator in the Laboratory for Nanophotonics at Rice during this time and was appointed Executive Director of the Rice Quantum Institute (RQI) by Director Peter Nordlander in 2000. This was a time of expansion for RQI, which eventually rose to 65 faculty members and their groups in departments throughout the Schools of Natural Sciences and Engineering. Johnson was involved in quintupling the size of the interdisciplinary Applied Physics Ph. D. Program and continuously running the interdisciplinary Research Experiences for Undergraduates site at RQI. From 2010 to 2014, he served in the Division of Chemistry at NSF, working with two programs, Chemical Theory, Models and Computational Methods (CTMC) and Macromolecular, Supramolecular and Nanochemistry (MSN), in proposal review and awards. At the end of 2014, he returned to Rice University to once again focus on theoretical research.