| Full text | |
| Author(s): |
Ujevic, Sebastian
;
Zampronio, Vinicius
;
de Abreu, Bruno R.
;
Vitiello, Silvio A.
Total Authors: 4
|
| Document type: | Journal article |
| Source: | SCIPOST PHYSICS CORE; v. 6, n. 2, p. 40-pg., 2023-04-01. |
| Abstract | |
We investigate strongly correlated many-body systems composed of bosons and fermions with a fully quantum treatment using the path-integral ground state method, PIGS. To account for the Fermi-Dirac statistics, we implement the fixed-node approximation into PIGS, which we then call FN-PIGS. In great detail, we discuss the pair density matrices we use to construct the full density operator in coordinate representation, a vital ingre-dient of the method. We consider the harmonic oscillator as a proof-of-concept and, as a platform representing quantum many-body systems, we explore helium atoms. Pure 4He systems demonstrate most of the features of the method. Complementarily, for pure 3He, the fixed-node approximation resolves the ubiquitous sign problem stemming from anti-symmetric wave functions. Finally, we investigate 3He-4He mixtures, demonstrating the method's robustness. One of the main features of FN-PIGS is its ability to estimate any property at temperature T = 0 without any additional bias apart from the FN ap-proximation; biases from long simulations are also excluded. In particular, we calculate the correlation function of pairs of equal and opposite spins and precise values of the 3He kinetic energy in the mixture. (AU) | |
| FAPESP's process: | 16/17612-7 - Dynamics of many-body systems IV |
| Grantee: | Arnaldo Gammal |
| Support Opportunities: | Research Projects - Thematic Grants |