A nonequilibrium time‐dependent functional theory based on Liouvillean quantum field dynamics
A. K. Rajagopal, F. A. Buot
Abstract A brief description of an extension of the time‐dependent functional theory to coupled field systems such as electron‐ion and electron–electromagnetic fields is given. This theory is further generalized to situations where the system is initially in thermodynamic equilibrium and is subjected to external time‐dependent probes which may drive the system out of equilibrium. Such a generalization is based on the Liouvillean quantum field dynamics (LQFD). The above formalism provides a firm physical and mathematical basis for time‐dependent simulation procedures such as those based on the Car–Parrinello approach by replacing the fictitious Lagrangian by a precise action principle. Several physical examples are given to illustrate the need for this formalism, where there is a necessity for treating all the field variables on equal footing and in a self‐consistent way. A new alternate formalism of time‐dependent functional theory based on a novel application of the Baym Φ‐derivable method is also given in terms of LQFD. By choosing suitable processes to set up the (D‐functional, our functional theory is transformed into a practical self‐consistent approach to the quantum many‐body equilibrium and transport problems, with built‐in conservation laws for all the physically relevant variables). © 1995 John Wiley & Sons, Inc.
International Journal of Quantum Chemistry•Nov 15, 1995•2 citations