On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard Model
We investigate the role of kinetic energy for the stability of superconducting state in the two-dimensional Hubbard model on the basis of an optimization variational Monte Carlo method. The wave function is optimized by multiplying by correlation operators of site off-diagonal type. This wave functi...
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MDPI AG
2021-02-01
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| Online Access: | https://www.mdpi.com/2410-3896/6/1/12 |
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| author | Takashi Yanagisawa Kunihiko Yamaji Mitake Miyazaki |
| author_facet | Takashi Yanagisawa Kunihiko Yamaji Mitake Miyazaki |
| author_sort | Takashi Yanagisawa |
| collection | DOAJ |
| description | We investigate the role of kinetic energy for the stability of superconducting state in the two-dimensional Hubbard model on the basis of an optimization variational Monte Carlo method. The wave function is optimized by multiplying by correlation operators of site off-diagonal type. This wave function is written in an exponential-type form given as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ψ</mi><mi>λ</mi></msub><mo>=</mo><mo form="prefix">exp</mo><mrow><mo>(</mo><mo>−</mo><mi>λ</mi><mi>K</mi><mo>)</mo></mrow><msub><mi>ψ</mi><mi>G</mi></msub></mrow></semantics></math></inline-formula> for the Gutzwiller wave function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ψ</mi><mi>G</mi></msub></semantics></math></inline-formula> and a kinetic operator <i>K</i>. The kinetic correlation operator <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo form="prefix">exp</mo><mo>(</mo><mo>−</mo><mi>λ</mi><mi>K</mi><mo>)</mo></mrow></semantics></math></inline-formula> plays an important role in the emergence of superconductivity in large-<i>U</i> region of the two-dimensional Hubbard model, where <i>U</i> is the on-site Coulomb repulsive interaction. We show that the superconducting condensation energy mainly originates from the kinetic energy in the strongly correlated region. This may indicate a possibility of high-temperature superconductivity due to the kinetic energy effect in correlated electron systems. |
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| language | English |
| last_indexed | 2024-03-09T00:29:34Z |
| publishDate | 2021-02-01 |
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| series | Condensed Matter |
| spelling | doaj.art-86e66f8c88f14fefbdf40ceb37c26a522023-12-11T18:36:03ZengMDPI AGCondensed Matter2410-38962021-02-01611210.3390/condmat6010012On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard ModelTakashi Yanagisawa0Kunihiko Yamaji1Mitake Miyazaki2National Institute of Advanced Industrial Science and Technology 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, JapanHakodate Institute of Technology, 14-1 Tokura, Hakodate, Hokkaido 042-8501, JapanNational Institute of Advanced Industrial Science and Technology 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, JapanWe investigate the role of kinetic energy for the stability of superconducting state in the two-dimensional Hubbard model on the basis of an optimization variational Monte Carlo method. The wave function is optimized by multiplying by correlation operators of site off-diagonal type. This wave function is written in an exponential-type form given as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>ψ</mi><mi>λ</mi></msub><mo>=</mo><mo form="prefix">exp</mo><mrow><mo>(</mo><mo>−</mo><mi>λ</mi><mi>K</mi><mo>)</mo></mrow><msub><mi>ψ</mi><mi>G</mi></msub></mrow></semantics></math></inline-formula> for the Gutzwiller wave function <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ψ</mi><mi>G</mi></msub></semantics></math></inline-formula> and a kinetic operator <i>K</i>. The kinetic correlation operator <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo form="prefix">exp</mo><mo>(</mo><mo>−</mo><mi>λ</mi><mi>K</mi><mo>)</mo></mrow></semantics></math></inline-formula> plays an important role in the emergence of superconductivity in large-<i>U</i> region of the two-dimensional Hubbard model, where <i>U</i> is the on-site Coulomb repulsive interaction. We show that the superconducting condensation energy mainly originates from the kinetic energy in the strongly correlated region. This may indicate a possibility of high-temperature superconductivity due to the kinetic energy effect in correlated electron systems.https://www.mdpi.com/2410-3896/6/1/12strongly correlated electronsmechanism of superconductivityhigh-temperature superconductortwo-dimensional Hubbard modeloptimization variational Monte Carlo methodHubbard model |
| spellingShingle | Takashi Yanagisawa Kunihiko Yamaji Mitake Miyazaki On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard Model Condensed Matter strongly correlated electrons mechanism of superconductivity high-temperature superconductor two-dimensional Hubbard model optimization variational Monte Carlo method Hubbard model |
| title | On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard Model |
| title_full | On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard Model |
| title_fullStr | On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard Model |
| title_full_unstemmed | On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard Model |
| title_short | On the Kinetic Energy Driven Superconductivity in the Two-Dimensional Hubbard Model |
| title_sort | on the kinetic energy driven superconductivity in the two dimensional hubbard model |
| topic | strongly correlated electrons mechanism of superconductivity high-temperature superconductor two-dimensional Hubbard model optimization variational Monte Carlo method Hubbard model |
| url | https://www.mdpi.com/2410-3896/6/1/12 |
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