On-site attractive multiorbital Hamiltonian ford-wave superconductors
| Autor: | Christopher B. Bishop, Elbio Dagotto, Guangkun Liu, Adriana Moreo |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Physics Superconductivity Condensed matter physics Hubbard model Condensed Matter - Superconductivity Fermi level FOS: Physical sciences 01 natural sciences Square lattice Superconductivity (cond-mat.supr-con) Brillouin zone 03 medical and health sciences symbols.namesake 030104 developmental biology Atomic orbital Condensed Matter::Superconductivity Pairing 0103 physical sciences symbols Condensed Matter::Strongly Correlated Electrons 010306 general physics Hamiltonian (quantum mechanics) |
| Zdroj: | Physical Review B. 93 |
| ISSN: | 2469-9969 2469-9950 |
| DOI: | 10.1103/physrevb.93.224519 |
| Popis: | We introduce a two-orbital Hamiltonian on a square lattice that contains on-site attractive interactions involving the two ${e}_{g}$ orbitals. Via a canonical mean-field procedure similar to the one applied to the well-known negative-$U$ Hubbard model, it is shown that the model develops $d$-wave (${B}_{1g}$) superconductivity with nodes along the diagonal directions of the square Brillouin zone. This result is also supported by exact diagonalization of the model in a small cluster. The expectation is that this relatively simple attractive model could be used to address the properties of multiorbital $d$-wave superconductors in the same manner that the negative-$U$ Hubbard model is widely applied to the study of the properties of $s$-wave single-orbital superconductors. In particular, we show that by splitting the ${e}_{g}$ orbitals and working at three-quarters filling, such that the ${x}^{2}\ensuremath{-}{y}^{2}$ orbital dominates at the Fermi level but the $3{z}^{2}\ensuremath{-}{r}^{2}$ orbital contribution is nonzero, the $d$-wave pairing state found here phenomenologically reproduces several properties of the superconducting state of the high ${T}_{c}$ cuprates. |
| Databáze: | OpenAIRE |
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