Special Issue Preface pubs.acs.org/JPCA
Tribute to Ronnie Kosloff both accurate and intuitive. This new framework made it possible to visualize quantum dynamics through the motion of localized quantum wavepackets. Ronnie’s new time-dependent framework was introduced in three major and highly cited papers that transformed the field of quantum chemical dynamics. Two papers, with his brother Dan Kosloff from Tel Aviv University as coauthor, established the Fourier grid method for quantum dynamics and the complex negative potential, enabling long time propagation on finite grids. A third paper, with mathematician Hillel Tal-Ezer as coauthor, introduced the Chebyshev polynomial method that allowed for highly accurate and highly efficient propagation of wave packets. These three seminal papers became the foundation of modern quantum chemical dynamics and had a huge impact on the field, as well as on many other fields of computational chemistry and physics. As it turns out, Ronnie’s revolutionary time-dependent framework also came just when it was needed the most for interpreting time-resolved pump−probe spectra measured by using novel ultrafast laser technology. Ronnie’s time-dependent methods turned out to be ideal for the theoretical study of this type of experiment. As a result, they were rapidly adopted by the ultrafast spectroscopy community and had a long-lasting impact on the field. This included a long-term collaboration with one of us (S.R.) on analysis of photodissociation dynamics and vibrational coherence transfer to product states, which demonstrated the interpretative strength of these methods. The introduction of ultrashort pulses also opened the door for using them not just as a probe but also as a way of actively controlling chemical dynamics. Ronnie was one of the first to recognize this, when together with David Tannor and Stuart Rice, he combined his time-dependent framework with the Tannor−Rice pump−dump control scheme, thereby giving birth to the new field of laser coherent control. Ronnie’s introduced some of the most powerful methods in this field, including the use of optimal control theory and original applications to laser cooling and quantum computing. Ronnie’s time-dependent methods also inspired breakthroughs in related fields. For example, his negative absorbing potentials led to new ways for calculating reaction rates and the electric conductance at molecular junctions. The Chebyshev expansion method was extended to calculate temperaturedependent reaction rate constants without the need for calculating energy-dependent reaction rates or the electronic density of states in large molecular systems. Ronnie has also made original contributions to the field of dissipative quantum dynamics. Here too, he remained true to his belief that both system and bath need to be treated fully quantum mechanically. Ronnie developed powerful, efficient, and intuitive schemes for solving the Lindblad semigroup equation and introduced the surrogate Hamiltonian method. He went on to use these methods to shed light on surface
Photo by Yaffa Kosloff
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t is our great privilege to dedicate this special issue of The Journal of Physical Chemistry A to Professor Ronnie Kosloff. Ronnie’s body of work is marked by creative, innovative, and transformative breakthroughs that gave rise to new areas of research and changed the very way we think, visualize, and talk about a wide range of topics at the heart of modern physical chemistry, including quantum dynamics of closed and open systems, surface chemistry, ultrafast spectroscopy, coherent control, laser cooling, and thermodynamics. In what follows, we highlight just a few of his many scientific accomplishments. Until the early 1980s, most studies of chemical reaction dynamics were based on either treating the dynamics as classical or treating it quantum mechanically, within the energy representation. The first approach provided an intuitive description of the dynamics but could not account for important quantum effects that arise from the wavelike nature of matter, such as tunneling, interference and zero-point energy. The second approach provided a rigorous and fully quantum mechanical description, but working in the energy representation made it inefficient and unintuitive, in the sense that it did not yield a description of the actual time-dependent motion of the wave function. In a series of pioneering papers during the early 1980s, Ronnie played a leading and crucial role in creating a new framework for simulating quantum dynamics in a way that was © 2016 American Chemical Society
Special Issue: Ronnie Kosloff Festschrift Published: May 19, 2016 2941
DOI: 10.1021/acs.jpca.6b00919 J. Phys. Chem. A 2016, 120, 2941−2942
The Journal of Physical Chemistry A
Special Issue Preface
chemistry, solution chemistry, and the effect of decoherence on coherent control and quantum computing. Another area that Ronnie left his mark on is quantum thermodynamics. Ronnie devoted his Ph.D. thesis to this topic and kept an active research program in this area throughout his career. His many contributions to this area that have attracted much attention in recent years include the development of quantum thermodynamics in finite time and the introduction of a time-dependent version of Nernst’s theorem, which imposes constraints on the rate of cooling as one approaches absolute zero. Over the years, Ronnie has distinguished himself as a theorist who has the rare ability and insight to develop methods that can be directly linked with state-of-the-art experiments. Ronnie also inspired generations of students as a teacher and mentor. The wide range of research interests pursued by ex-members of the Kosloff group that hold faculty positions in universities in Israel and around the world, as well as research positions in industry and in governmental research institutes, is a testimony and a tribute to Ronnie’s unique research style, which emphasized fearless and uncompromising pursuit of the most challenging problems and a search for the most honest description of the systems under study. In addition to his distinguished research career, Ronnie has also been a role model when it comes to service to the community, including serving as head of the school of Chemistry at The Hebrew University, head of the Amirim program at The Hebrew University, head of Natural Sciences division of The Israeli National Science Foundation, director of the Fritz Haber center for Chemical Dynamics, and curriculum development that included specialized software for teaching quantum dynamics. In many ways, Ronnie has played a key role in shaping us as scientists and as people. We feel privileged for having the opportunity to work with him and are grateful to him for all that he has taught us throughout the years. Dedicating this issue to him is our way of saying thank you and an opportunity to wish him many more years of scientific discovery, world travel, skiing, and good wine.
Eitan Geva Sanford Ruhman
2942
DOI: 10.1021/acs.jpca.6b00919 J. Phys. Chem. A 2016, 120, 2941−2942
