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| Autores principales: | , , , , , , |
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| Formato: | Preprint |
| Publicado: |
2024
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| Materias: | |
| Acceso en línea: | https://arxiv.org/abs/2404.05541 |
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| _version_ | 1866912144315908096 |
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| author | Dirnböck, Selina Lee, Seung-Sup B. Kugler, Fabian B. Huber, Sebastian von Delft, Jan Held, Karsten Wallerberger, Markus |
| author_facet | Dirnböck, Selina Lee, Seung-Sup B. Kugler, Fabian B. Huber, Sebastian von Delft, Jan Held, Karsten Wallerberger, Markus |
| contents | Two-particle response functions are a centerpiece of both experimental and theoretical quantum many-body physics. Yet, due to their size and discontinuity structure, they are challenging to handle numerically. Recently, two advances were made to tackle this problem: first, the overcomplete intermediate representation (OIR), which provides a highly efficient compression of Green's functions in imaginary frequency, and second, partial spectral functions (PSFs), which allow for an efficient evaluation in real frequency. We show that there is a two-to-one correspondence between PSFs and OIR coefficients and exploit this fact to construct the OIR for three-or-more-particle propagators. We then use OIR to fit and compress imaginary-frequency data obtained from the numerical renormalization group (NRG), reaching a compression ratio of more than 400. Finally, we attempt to match the OIR data to partial Green's functions from NRG.Due to the overcompleteness, we achieve only qualitative agreement. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2404_05541 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Overcomplete intermediate representation of two-particle Green's functions and its relation to partial spectral functions Dirnböck, Selina Lee, Seung-Sup B. Kugler, Fabian B. Huber, Sebastian von Delft, Jan Held, Karsten Wallerberger, Markus Strongly Correlated Electrons Two-particle response functions are a centerpiece of both experimental and theoretical quantum many-body physics. Yet, due to their size and discontinuity structure, they are challenging to handle numerically. Recently, two advances were made to tackle this problem: first, the overcomplete intermediate representation (OIR), which provides a highly efficient compression of Green's functions in imaginary frequency, and second, partial spectral functions (PSFs), which allow for an efficient evaluation in real frequency. We show that there is a two-to-one correspondence between PSFs and OIR coefficients and exploit this fact to construct the OIR for three-or-more-particle propagators. We then use OIR to fit and compress imaginary-frequency data obtained from the numerical renormalization group (NRG), reaching a compression ratio of more than 400. Finally, we attempt to match the OIR data to partial Green's functions from NRG.Due to the overcompleteness, we achieve only qualitative agreement. |
| title | Overcomplete intermediate representation of two-particle Green's functions and its relation to partial spectral functions |
| topic | Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2404.05541 |