Isotope effect on the superconducting critical temperature of cuprates in the presence of charge order
Using the large-N limit of the t–J model and also allowing for phonons and the electron–phonon interaction, we study the isotope effect α for coupling constants appropriate for YB2C3O y . We find that α has a minimum at optimal doping and increases strongly (slightly) towards the underdoped (overdop...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/13401 |
| Acceso en línea: | http://hdl.handle.net/11336/13401 |
| Access Level: | acceso abierto |
| Palabra clave: | Phonons Cuprates superconductors Pseudogap Regime https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 |
| Sumario: | Using the large-N limit of the t–J model and also allowing for phonons and the electron–phonon interaction, we study the isotope effect α for coupling constants appropriate for YB2C3O y . We find that α has a minimum at optimal doping and increases strongly (slightly) towards the underdoped (overdoped) region. Using values for the electron–phonon interaction from the local density approximation we get good agreement for α as a function of T c and doping δ with recent experimental data in YB2C3O y . Our results strongly suggest that the large increase of α in the underdoped region is (a) caused by the shift of electronic spectral density from low to high energies associated with a competing phase (in our case a charge density wave) and the formation of a gap, and (b) compatible with the small electron–phonon coupling constants obtained from the local density approximation. We propose a similar explanation for the anomalous behavior of α in Sr-doped La2CuO4 near the doping 1/8. |
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