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Reduced density matrix approach to ultracold few-fermion systems in one dimension
- Source :
- New Journal of Physics, Vol 24, Iss 5, p 053004 (2022)
- Publication Year :
- 2022
- Publisher :
- IOP Publishing, 2022.
-
Abstract
- The variational determination of the two-fermion reduced density matrix (2-RDM) is described for harmonically trapped, ultracold few-fermion systems in one dimension with equal spin populations. This is accomplished by formulating the problem as a semi-definite program, with the 2-RDM being subject to well-known N -representability conditions. The ground-state energies, as well as the density, pair-correlation function, and lower-order eigenvalues of the 2-RDM of various fermionic systems are found by utilising an augmented Lagrangian method for semi-definite programming. The ground-state energies are found to match well to those determined by full-configuration interaction and coupled-cluster calculations and the density, pair-correlation function, and eigenvalue results demonstrate that the salient features of these systems are well-described by this method. These results collectively demonstrate the utility of the reduced density matrix method firstly in describing strong correlation arising from short-range interactions, suggesting that the well-known N -representability conditions are sufficient to model ultracold fermionic systems, and secondly in illustrating the prospect of treating larger systems currently out of the reach of established methods.
- Subjects :
- quantum Fermi gas
few body physics
reduced density matrix
Science
Physics
QC1-999
Subjects
Details
- Language :
- English
- ISSN :
- 13672630
- Volume :
- 24
- Issue :
- 5
- Database :
- Directory of Open Access Journals
- Journal :
- New Journal of Physics
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.7601402b4af4f35b32865ba86528b2c
- Document Type :
- article
- Full Text :
- https://doi.org/10.1088/1367-2630/ac643d