We evaluate imaginary time density-density correlation functions for two-dimensional homogeneous electron gases of up to 42 particles in the continuum using the phaseless auxiliary field quantum Monte Carlo method. We use periodic boundary conditions and up to 300 plane waves as basis set elements. We show that such methodology, once equipped with suitable numerical stabilization techniques necessary to deal with exponentials, products, and inversions of large matrices, gives access to the calculation of imaginary time correlation functions for medium-sized systems. We discuss the numerical stabilization techniques and the computational complexity of the methodology and we present the limitations related to the size of the systems on a quantitative basis. We perform the inverse Laplace transform of the obtained density-density correlation functions, assessing the ability of the phaseless auxiliary field quantum Monte Carlo method to evaluate dynamical properties of medium-sized homogeneous fermion systems.

Imaginary time density-density correlations for two-dimensional electron gases at high density / M. Motta, D.E. Galli, S. Moroni, E. Vitali. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 143:16(2015 Oct 28), pp. 164108.1-164108.14. [10.1063/1.4934666]

Imaginary time density-density correlations for two-dimensional electron gases at high density

M. Motta
Primo
;
D.E. Galli
;
2015-10-28

Abstract

We evaluate imaginary time density-density correlation functions for two-dimensional homogeneous electron gases of up to 42 particles in the continuum using the phaseless auxiliary field quantum Monte Carlo method. We use periodic boundary conditions and up to 300 plane waves as basis set elements. We show that such methodology, once equipped with suitable numerical stabilization techniques necessary to deal with exponentials, products, and inversions of large matrices, gives access to the calculation of imaginary time correlation functions for medium-sized systems. We discuss the numerical stabilization techniques and the computational complexity of the methodology and we present the limitations related to the size of the systems on a quantitative basis. We perform the inverse Laplace transform of the obtained density-density correlation functions, assessing the ability of the phaseless auxiliary field quantum Monte Carlo method to evaluate dynamical properties of medium-sized homogeneous fermion systems.
Physics and Astronomy (all); Physical and Theoretical Chemistry
Settore FIS/03 - Fisica della Materia
Article (author)
File in questo prodotto:
File Dimensione Formato  
AFQMC_2.pdf

accesso aperto

Tipologia: Publisher's version/PDF
Dimensione 1.1 MB
Formato Adobe PDF
1.1 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/336641
Citazioni
  • ???jsp.display-item.citation.pmc??? 0
  • Scopus 22
  • ???jsp.display-item.citation.isi??? 22
social impact