Real-Time Time-Dependent Electronic Structure Theory09 Oct 2017
I have a new review on (and titled) real-time time-dependent electronic structure theory out now, which has been one of my active research areas over the past five years or so. Like other electronic structure methods, real-time time-dependent (RT-TD) methods seeks to understand molecules through a quantum treatment of the motions of their electrons. What sets RT-TD theories and methods apart is that they explore how electrons evolve in time, especially as they respond to things like lasers, magnetic fields, X-rays, and so on. Real time methods look at molecular responses to these things explicitly in time, and gives an intuitive and dynamic view of how molecules behave under all sorts of experimental conditions. From this, we can predict and explain how certain molecules make better candidates for solar energy conversion, molecular electronics, or nanosensors, etc.
The truth is that there is a wealth of information that can be obtained by real-time time-dependent methods. Because of this, RT-TD methods are often criticized as inefficient and overkill for many predictive applications. In some cases this is true, for example when computing absorption spectra of small organic molecules (linear response methods are usually a better choice). However, to dismiss all RT-TD methods is a mistake, as the methods comprise a general technique for studying extremely complex phenomena. RT-TD methods allow for complete control over the number and strength of interacting external perturbations (multiple intense lasers, for example) in the study of molecular responses. In the review, we address many of these unique applications, ranging from non-equilibrium solvent dynamics to dynamic hyperpolarizability to the emerging real-time quantum electrodynamics (QED), where even the photon field is quantized.
The article was extremely fun to write, and I hope you find something useful and interesting in it. RT-TD comprises a broad field with extremely talented scientists working on its development. You can find the article here.