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Sum rule violation in self-consistent hybridization expansions.
- Source :
-
Physical Review B: Condensed Matter & Materials Physics . Feb2013, Vol. 87 Issue 7, p075124-1-075124-11. 11p. - Publication Year :
- 2013
-
Abstract
- We show that for multiorbital quantum impurity models the noncrossing approximation and one-crossing approximation versions of the self-consistent hybridization expansions violate the sum rules relating the coefficients of the high-frequency expansion of the self-energy and the product of the self-energy and Green's function to thermodynamic expectation values. Comparison of noncrossing/one-crossing results to numerically exact quantum Monte Carlo calculations shows that the consistency with sum rules provides a useful estimate of the reliability of the approximations. The sum rule violations are more pronounced, and therefore the quality of the noncrossing/one-crossing approximation is poorer, in situations with multiple orbitals and away from particle-hole symmetry but becomes less severe as the correlation strength increases. The one-crossing approximation is markedly superior to the noncrossing approximation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10980121
- Volume :
- 87
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- Physical Review B: Condensed Matter & Materials Physics
- Publication Type :
- Academic Journal
- Accession number :
- 86730248
- Full Text :
- https://doi.org/10.1103/PhysRevB.87.075124