Enhanced pair correlation functions in the two-dimensional Hubbard model
In this study we have computed the pair correlation functions in the two-dimensional Hubbard model using a quantum Monte Carlo method. We employ a new diagonalization algorithm in the quantum Monte Carlo method which is free from the negative sign problem. We show that the d-wave pairing correlation...
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2013-01-01
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| Series: | New Journal of Physics |
| Online Access: | https://doi.org/10.1088/1367-2630/15/3/033012 |
| _version_ | 1797751695894118400 |
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| author | Takashi Yanagisawa |
| author_facet | Takashi Yanagisawa |
| author_sort | Takashi Yanagisawa |
| collection | DOAJ |
| description | In this study we have computed the pair correlation functions in the two-dimensional Hubbard model using a quantum Monte Carlo method. We employ a new diagonalization algorithm in the quantum Monte Carlo method which is free from the negative sign problem. We show that the d-wave pairing correlation function is indeed enhanced slightly for the positive on-site Coulomb interaction U when doping away from the half-filling. When the system size becomes large, the pair correlation function P _d increases for U > 0 compared to the non-interacting case, while P _d is suppressed for U > 0 when the system size is small. The enhancement ratio P _d [ U ]/ P _d [ U = 0] will give a criterion on the existence of superconductivity. The ratio P _d [ U ]/ P _d [ U = 0] increases almost linearly ∝ L when the system size L × L is increased. This increase is a good indication of the existence of a superconducting phase in the two-dimensional Hubbard model. There is, however, no enhancement of pair correlation functions in the half-filled case, which indicates the absence of superconductivity without hole doping. |
| first_indexed | 2024-03-12T16:52:20Z |
| format | Article |
| id | doaj.art-249176697224404ba4599b50d8ea5991 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:52:20Z |
| publishDate | 2013-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-249176697224404ba4599b50d8ea59912023-08-08T11:05:16ZengIOP PublishingNew Journal of Physics1367-26302013-01-0115303301210.1088/1367-2630/15/3/033012Enhanced pair correlation functions in the two-dimensional Hubbard modelTakashi Yanagisawa0Electronics and Photonics Research Institute , National Institute of Advanced Industrial Science and Technology (AIST), Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, JapanIn this study we have computed the pair correlation functions in the two-dimensional Hubbard model using a quantum Monte Carlo method. We employ a new diagonalization algorithm in the quantum Monte Carlo method which is free from the negative sign problem. We show that the d-wave pairing correlation function is indeed enhanced slightly for the positive on-site Coulomb interaction U when doping away from the half-filling. When the system size becomes large, the pair correlation function P _d increases for U > 0 compared to the non-interacting case, while P _d is suppressed for U > 0 when the system size is small. The enhancement ratio P _d [ U ]/ P _d [ U = 0] will give a criterion on the existence of superconductivity. The ratio P _d [ U ]/ P _d [ U = 0] increases almost linearly ∝ L when the system size L × L is increased. This increase is a good indication of the existence of a superconducting phase in the two-dimensional Hubbard model. There is, however, no enhancement of pair correlation functions in the half-filled case, which indicates the absence of superconductivity without hole doping.https://doi.org/10.1088/1367-2630/15/3/033012 |
| spellingShingle | Takashi Yanagisawa Enhanced pair correlation functions in the two-dimensional Hubbard model New Journal of Physics |
| title | Enhanced pair correlation functions in the two-dimensional Hubbard model |
| title_full | Enhanced pair correlation functions in the two-dimensional Hubbard model |
| title_fullStr | Enhanced pair correlation functions in the two-dimensional Hubbard model |
| title_full_unstemmed | Enhanced pair correlation functions in the two-dimensional Hubbard model |
| title_short | Enhanced pair correlation functions in the two-dimensional Hubbard model |
| title_sort | enhanced pair correlation functions in the two dimensional hubbard model |
| url | https://doi.org/10.1088/1367-2630/15/3/033012 |
| work_keys_str_mv | AT takashiyanagisawa enhancedpaircorrelationfunctionsinthetwodimensionalhubbardmodel |