Unitary evolution with fluctuations and dissipation

TL;DR

This paper extends the quantum Langevin equation within density functional theory to model dissipation and fluctuations in many-fermion systems, demonstrated through fission fragment yield calculations.

Contribution

It introduces a novel quantum approach combining Langevin dynamics with density functional theory for collective degrees of freedom.

Findings

Successfully computed fission fragment distributions for $^{258}$Fm.

Demonstrated the method with a quantum hydrodynamic approach.

Showed the approach's capability with unrestricted density functional theory.

Abstract

We outline an extension of the classical Langevin equation to a quantum formulation of the treatment of dissipation and fluctuations of all collective degrees of freedom with unitary evolution of a many-fermion system within an extension of the time-dependent density functional theory. We illustrate the method by computing the distribution of fission fragment yields for $^{258}$Fm in a quantum hydrodynamic approach and a typical trajectory with full unrestricted density functional theory augmented with dissipation and fluctuations.