Phase Separation and Pairing Fluctuations in Oxide Materials
The microscopic mechanism of charge instabilities and the formation of inhomogeneous states in systems with strong electron correlations is investigated. We demonstrate that within a strong coupling expansion the single-band Hubbard model shows an instability towards phase separation and extend the...
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MDPI AG
2020-10-01
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| Series: | Condensed Matter |
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| Online Access: | https://www.mdpi.com/2410-3896/5/4/65 |
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| author | Andreas Bill Vladimir Hizhnyakov Reinhard K. Kremer Götz Seibold Aleksander Shelkan Alexei Sherman |
| author_facet | Andreas Bill Vladimir Hizhnyakov Reinhard K. Kremer Götz Seibold Aleksander Shelkan Alexei Sherman |
| author_sort | Andreas Bill |
| collection | DOAJ |
| description | The microscopic mechanism of charge instabilities and the formation of inhomogeneous states in systems with strong electron correlations is investigated. We demonstrate that within a strong coupling expansion the single-band Hubbard model shows an instability towards phase separation and extend the approach also for an analysis of phase separation in the Hubbard-Kanamori hamiltonian as a prototypical multiband model. We study the pairing fluctuations on top of an inhomogeneous stripe state where superconducting correlations in the extended <i>s</i>-wave and <i>d</i>-wave channels correspond to (anti)bound states in the two-particle spectra. Whereas extended <i>s</i>-wave fluctuations are relevant on the scale of the local interaction parameter <i>U</i>, we find that <i>d</i>-wave fluctuations are pronounced in the energy range of the active subband which crosses the Fermi level. As a result, low energy spin and charge fluctuations can transfer the <i>d</i>-wave correlations from the bound states to the low energy quasiparticle bands. Our investigations therefore help to understand the coexistence of stripe correlations and <i>d</i>-wave superconductivity in cuprates. |
| first_indexed | 2024-03-10T15:30:42Z |
| format | Article |
| id | doaj.art-95b4fbdb912545b3849d44328f9719b4 |
| institution | Directory Open Access Journal |
| issn | 2410-3896 |
| language | English |
| last_indexed | 2024-03-10T15:30:42Z |
| publishDate | 2020-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Condensed Matter |
| spelling | doaj.art-95b4fbdb912545b3849d44328f9719b42023-11-20T17:42:46ZengMDPI AGCondensed Matter2410-38962020-10-01546510.3390/condmat5040065Phase Separation and Pairing Fluctuations in Oxide MaterialsAndreas Bill0Vladimir Hizhnyakov1Reinhard K. Kremer2Götz Seibold3Aleksander Shelkan4Alexei Sherman5Department of Physics & Astronomy, California State University Long Beach, Long Beach, CA 90840, USAInstitute of Physics, University of Tartu, 1 W. Ostwaldi Street, 50411 Tartu, EstoniaMPI for Solid State Research Heisenbergstraße 1, 70569 Stuttgart, GermanyInstitut für Physik, BTU Cottbus, P.O. Box 101344, 03013 Cottbus, GermanyInstitute of Physics, University of Tartu, 1 W. Ostwaldi Street, 50411 Tartu, EstoniaInstitute of Physics, University of Tartu, 1 W. Ostwaldi Street, 50411 Tartu, EstoniaThe microscopic mechanism of charge instabilities and the formation of inhomogeneous states in systems with strong electron correlations is investigated. We demonstrate that within a strong coupling expansion the single-band Hubbard model shows an instability towards phase separation and extend the approach also for an analysis of phase separation in the Hubbard-Kanamori hamiltonian as a prototypical multiband model. We study the pairing fluctuations on top of an inhomogeneous stripe state where superconducting correlations in the extended <i>s</i>-wave and <i>d</i>-wave channels correspond to (anti)bound states in the two-particle spectra. Whereas extended <i>s</i>-wave fluctuations are relevant on the scale of the local interaction parameter <i>U</i>, we find that <i>d</i>-wave fluctuations are pronounced in the energy range of the active subband which crosses the Fermi level. As a result, low energy spin and charge fluctuations can transfer the <i>d</i>-wave correlations from the bound states to the low energy quasiparticle bands. Our investigations therefore help to understand the coexistence of stripe correlations and <i>d</i>-wave superconductivity in cuprates.https://www.mdpi.com/2410-3896/5/4/65phase separationcuprate superconductorselectronic correlations |
| spellingShingle | Andreas Bill Vladimir Hizhnyakov Reinhard K. Kremer Götz Seibold Aleksander Shelkan Alexei Sherman Phase Separation and Pairing Fluctuations in Oxide Materials Condensed Matter phase separation cuprate superconductors electronic correlations |
| title | Phase Separation and Pairing Fluctuations in Oxide Materials |
| title_full | Phase Separation and Pairing Fluctuations in Oxide Materials |
| title_fullStr | Phase Separation and Pairing Fluctuations in Oxide Materials |
| title_full_unstemmed | Phase Separation and Pairing Fluctuations in Oxide Materials |
| title_short | Phase Separation and Pairing Fluctuations in Oxide Materials |
| title_sort | phase separation and pairing fluctuations in oxide materials |
| topic | phase separation cuprate superconductors electronic correlations |
| url | https://www.mdpi.com/2410-3896/5/4/65 |
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