Accuracy of ghost-rotationally-invariant slave-boson and dynamical mean field theory as a function of the impurity-model bath size
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2022
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| author | Lee, Tsung-Han Lanatà, Nicola Kotliar, Gabriel |
| author_facet | Lee, Tsung-Han Lanatà, Nicola Kotliar, Gabriel |
| contents | We compare the accuracy of the ghost-rotationally-invariant slave-boson (g-RISB) theory and dynamical mean-field theory (DMFT) on the single-band Hubbard model, as a function of the number of bath sites in the embedding impurity Hamiltonian. Our benchmark calculations confirm that the accuracy of g-RISB can be systematically improved by increasing the number of bath sites, similar to DMFT. With a few bath sites, we observe that g-RISB is systematically more accurate than DMFT for the ground-state observables. On the other hand, the relative accuracy of these methods is generally comparable for the quasiparticle weight and the spectral function. As expected, we observe that g-RISB satisfies the variational principle in infinite dimensions, as the total energy decreases monotonically towards the exact value as a function of the number of bath sites, suggesting that the g-RISB wavefunction may approach the exact ground state in infinite dimensions. Our results suggest that the g-RISB is a promising method for first principle simulations of strongly correlated matter, which can capture the behavior of both static and dynamical observables, at a relatively low computational cost. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2212_07515 |
| institution | arXiv |
| publishDate | 2022 |
| record_format | arxiv |
| spellingShingle | Accuracy of ghost-rotationally-invariant slave-boson and dynamical mean field theory as a function of the impurity-model bath size Lee, Tsung-Han Lanatà, Nicola Kotliar, Gabriel Strongly Correlated Electrons We compare the accuracy of the ghost-rotationally-invariant slave-boson (g-RISB) theory and dynamical mean-field theory (DMFT) on the single-band Hubbard model, as a function of the number of bath sites in the embedding impurity Hamiltonian. Our benchmark calculations confirm that the accuracy of g-RISB can be systematically improved by increasing the number of bath sites, similar to DMFT. With a few bath sites, we observe that g-RISB is systematically more accurate than DMFT for the ground-state observables. On the other hand, the relative accuracy of these methods is generally comparable for the quasiparticle weight and the spectral function. As expected, we observe that g-RISB satisfies the variational principle in infinite dimensions, as the total energy decreases monotonically towards the exact value as a function of the number of bath sites, suggesting that the g-RISB wavefunction may approach the exact ground state in infinite dimensions. Our results suggest that the g-RISB is a promising method for first principle simulations of strongly correlated matter, which can capture the behavior of both static and dynamical observables, at a relatively low computational cost. |
| title | Accuracy of ghost-rotationally-invariant slave-boson and dynamical mean field theory as a function of the impurity-model bath size |
| topic | Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2212.07515 |