Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard Model
The emergence of superconductivity (SC) in lattice models, such as the attractive Hubbard one, has renewed interest since the realization of cold-atom experiments. However, reducing the temperature in these experiments is a bottleneck; therefore, investigating how to increase the energy scale for SC...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-01-01
|
| Series: | Condensed Matter |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2410-3896/8/1/11 |
| _version_ | 1797612548782030848 |
|---|---|
| author | Rodrigo Alves Fontenele Nathan Vasconcelos Natanael Carvalho Costa Thereza Paiva Raimundo Rocha dos Santos |
| author_facet | Rodrigo Alves Fontenele Nathan Vasconcelos Natanael Carvalho Costa Thereza Paiva Raimundo Rocha dos Santos |
| author_sort | Rodrigo Alves Fontenele |
| collection | DOAJ |
| description | The emergence of superconductivity (SC) in lattice models, such as the attractive Hubbard one, has renewed interest since the realization of cold-atom experiments. However, reducing the temperature in these experiments is a bottleneck; therefore, investigating how to increase the energy scale for SC is crucial to cold atoms. In view of this, we examine the effects of next-nearest-neighbor hoppings (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>t</mi><mo>′</mo></msup></semantics></math></inline-formula>) on the pairing properties of the attractive Hubbard model in a square lattice. To this end, we analyze the model through unbiased Quantum Monte Carlo simulations for fixed density <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>n</mi><mo>=</mo><mn>0.87</mn></mrow></semantics></math></inline-formula>, and perform finite-size scaling analysis to the thermodynamic limit. As our main result, we notice that the existence of further hopping channels leads to an enhancement of the pairing correlations, which, in turn, increases the ground-state order parameter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Δ</mo></semantics></math></inline-formula>. Finally, at finite temperatures, for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>t</mi><mo>′</mo></msup><mo>/</mo><mi>t</mi><mo>≠</mo><mn>0</mn></mrow></semantics></math></inline-formula>, this enhancement of pairing correlations leads to an increase in the critical temperature <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>T</mi><mi>c</mi></msub></semantics></math></inline-formula>. That is, the fine-tuning of second-neighbor hoppings increases the energy scales for SC, and may be a route by which cold-atom experiments can achieve such a phase and to help us further understand the nature of this phenomenon. |
| first_indexed | 2024-03-11T06:42:46Z |
| format | Article |
| id | doaj.art-69067053233146ceb2473daef4c75572 |
| institution | Directory Open Access Journal |
| issn | 2410-3896 |
| language | English |
| last_indexed | 2024-03-11T06:42:46Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Condensed Matter |
| spelling | doaj.art-69067053233146ceb2473daef4c755722023-11-17T10:26:47ZengMDPI AGCondensed Matter2410-38962023-01-01811110.3390/condmat8010011Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard ModelRodrigo Alves Fontenele0Nathan Vasconcelos1Natanael Carvalho Costa2Thereza Paiva3Raimundo Rocha dos Santos4Instituto de Física, Universidade Federal do Rio de Janeiro, Cx.P. 68.528, Rio de Janeiro 21941-972, BrazilInstituto de Física, Universidade Federal do Rio de Janeiro, Cx.P. 68.528, Rio de Janeiro 21941-972, BrazilInstituto de Física, Universidade Federal do Rio de Janeiro, Cx.P. 68.528, Rio de Janeiro 21941-972, BrazilInstituto de Física, Universidade Federal do Rio de Janeiro, Cx.P. 68.528, Rio de Janeiro 21941-972, BrazilInstituto de Física, Universidade Federal do Rio de Janeiro, Cx.P. 68.528, Rio de Janeiro 21941-972, BrazilThe emergence of superconductivity (SC) in lattice models, such as the attractive Hubbard one, has renewed interest since the realization of cold-atom experiments. However, reducing the temperature in these experiments is a bottleneck; therefore, investigating how to increase the energy scale for SC is crucial to cold atoms. In view of this, we examine the effects of next-nearest-neighbor hoppings (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>t</mi><mo>′</mo></msup></semantics></math></inline-formula>) on the pairing properties of the attractive Hubbard model in a square lattice. To this end, we analyze the model through unbiased Quantum Monte Carlo simulations for fixed density <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>n</mi><mo>=</mo><mn>0.87</mn></mrow></semantics></math></inline-formula>, and perform finite-size scaling analysis to the thermodynamic limit. As our main result, we notice that the existence of further hopping channels leads to an enhancement of the pairing correlations, which, in turn, increases the ground-state order parameter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Δ</mo></semantics></math></inline-formula>. Finally, at finite temperatures, for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>t</mi><mo>′</mo></msup><mo>/</mo><mi>t</mi><mo>≠</mo><mn>0</mn></mrow></semantics></math></inline-formula>, this enhancement of pairing correlations leads to an increase in the critical temperature <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>T</mi><mi>c</mi></msub></semantics></math></inline-formula>. That is, the fine-tuning of second-neighbor hoppings increases the energy scales for SC, and may be a route by which cold-atom experiments can achieve such a phase and to help us further understand the nature of this phenomenon.https://www.mdpi.com/2410-3896/8/1/11superconductivityHubbard modelquantum Monte Carlo |
| spellingShingle | Rodrigo Alves Fontenele Nathan Vasconcelos Natanael Carvalho Costa Thereza Paiva Raimundo Rocha dos Santos Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard Model Condensed Matter superconductivity Hubbard model quantum Monte Carlo |
| title | Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard Model |
| title_full | Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard Model |
| title_fullStr | Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard Model |
| title_full_unstemmed | Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard Model |
| title_short | Second-Neighbor Hopping Effects in the Two-Dimensional Attractive Hubbard Model |
| title_sort | second neighbor hopping effects in the two dimensional attractive hubbard model |
| topic | superconductivity Hubbard model quantum Monte Carlo |
| url | https://www.mdpi.com/2410-3896/8/1/11 |
| work_keys_str_mv | AT rodrigoalvesfontenele secondneighborhoppingeffectsinthetwodimensionalattractivehubbardmodel AT nathanvasconcelos secondneighborhoppingeffectsinthetwodimensionalattractivehubbardmodel AT natanaelcarvalhocosta secondneighborhoppingeffectsinthetwodimensionalattractivehubbardmodel AT therezapaiva secondneighborhoppingeffectsinthetwodimensionalattractivehubbardmodel AT raimundorochadossantos secondneighborhoppingeffectsinthetwodimensionalattractivehubbardmodel |