Multipole strength function of deformed superfluid nuclei made easy

TL;DR

This paper introduces an efficient finite amplitude method (FAM) for calculating strength functions in deformed superfluid nuclei, significantly reducing computational costs while maintaining accuracy, enabling large-scale nuclear structure studies.

Contribution

The paper presents a novel FAM implementation based on Broyden's iterative procedure that simplifies and accelerates strength function calculations in deformed superfluid nuclei.

Findings

FAM reproduces QRPA strength functions accurately

Method reduces computational cost substantially

Enables large-scale nuclear structure calculations

Abstract

We present an efficient method for calculating strength functions using the finite amplitude method (FAM) for deformed superfluid heavy nuclei within the framework of the nuclear density functional theory. We demonstrate that FAM reproduces strength functions obtained with the fully self-consistent quasi-particle random-phase approximation (QRPA) at a fraction of computational cost. As a demonstration, we compute the isoscalar and isovector monopole strength for strongly deformed configurations in $^{240}$Pu by considering huge quasi-particle QRPA spaces. Our approach to FAM, based on Broyden's iterative procedure, opens the possibility for large-scale calculations of strength distributions in well-bound and weakly bound nuclei across the nuclear landscape.