TITLE:
Optimizing the Computation of Many-Pair Density Matrix in VDPC
AUTHORS:
Jin Li, Wanli Ma
KEYWORDS:
Nuclear Structure, Mean-Field Theory, BCS, Density Matrix, VDPC
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.10 No.7,
July
28,
2022
ABSTRACT: Recently an algorithm that acts the variational principle directly to a coherent-pair condensate (VDPC) has been proposed. This algorithm can avoid time-consuming projection while maintaining particle number conservation. Quickly computation of many-pair density matrix (MPDM) is one of the keys to improve the computational efficiency of VDPC algorithm. In this work, we propose a scheme that limits the energy range of block particles to the vicinity of the Fermi surface, which reduces the time complexity of computing the MPDM without losing physical details. The results show that by appropriately limiting the energy range, we can greatly reduce the number of matrix elements that need to be computed, and reducing the time required for the computation.