On-site attractive multiorbital Hamiltonian for d-wave superconductors | |
Article | |
关键词: ELECTRONIC-STRUCTURE; PHASE-SEPARATION; HUBBARD; SYMMETRY; STATE; MODEL; | |
DOI : 10.1103/PhysRevB.93.224519 | |
来源: SCIE |
【 摘 要 】
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) - y(2) orbital dominates at the Fermi level but the 3z(2) - 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)d cuprates.
【 授权许可】
Free