Semiclassical Electron Correlation in Density-Matrix Time Propagation

Semiclassical electron correlation in density-matrix time propagation.

Lack of memory (locality in time) is a major limitation of almost all present time-dependent density-functional approximations. By using semiclassical dynamics to compute correlation effects in the time propagation of the density matrix, we incorporate memory, including initial-state dependence, as well as changing occupation numbers, and predict more observables in strong-field applications.

Density-Matrix Propagation Driven by Semiclassical Correlation

Methods based on propagation of the one-body reduced density-matrix hold much promise for the simulation of correlated many-electron dynamics far from equilibrium, but difficulties with finding good approximations for the interaction term in its equation of motion have so far impeded their application. These difficulties include the violation of fundamental physical principles such as energy co...

Semiclassical Correlation in Time-Dependent Density Matrix Functional Theory

The impact of time-dependent density functional theory (TDDFT) [1, 2] on calculations of excitation spectra and response in atoms, molecules, and solids is evident in its increasing use. In such applications a weak perturbation is applied to the system beginning in its ground state, and usually the exchange-correlation (xc) effects are treated with a ground-state approximation. Generally the re...

Improved semiclassical density matrix: taming caustics.

We present a simple method to deal with caustics in the semiclassical approximation to the thermal density matrix of a particle moving on the line. For simplicity, only its diagonal elements are considered. The only ingredient we require is the knowledge of the extrema of the Euclidean action. The procedure makes use of complex trajectories, and is applied to the quartic double-well potential.

Simplified Semiclassical Propagation Estimates