We compute the ground-state phase diagram of the three-band Hubbard model in various published parametrizations using density matrix embedding theory. We study the atomic-scale nature of the antiferromagnetic (AF) and superconducting (SC) orders, explicitly including the oxygen degrees of freedom. In the case of the AF order, as expected, the local magnetic moment localizes entirely at the copper sites and decays with doping, while in the SC phase we observe a local $p_{x (y)}$ [or $d_{xz (yz)}$ ]-symmetry modulation of the pair density on the Cu-O bonds within the larger scale $d_{x^2 - y^2}$ -wave SC pairing order between Cu-Cu and O-O. While all parametrizations of the model display AF and SC phases, the decay of AF order with doping is too slow compared to the experimental phase diagram, and further, coexistence of AF and SC orders occurs in all parameter sets. Our work highlights the importance of the oxygen degrees of freedom in the study of atomic-scale SC orders, as well as the necessity of re-evaluating current parametrizations of the three-band Hubbard model.We compute the ground-state phase diagram of the three-band Hubbard model in various published parametrizations using density matrix embedding theory. We study the atomic-scale nature of the antiferromagnetic (AF) and superconducting (SC) orders, explicitly including the oxygen degrees of freedom. In the case of the AF order, as expected, the local magnetic moment localizes entirely at the copper sites and decays with doping, while in the SC phase we observe a local $p_{x (y)}$ [or $d_{xz (yz)}$]-symmetry modulation of the pair density on the Cu-O bonds within the larger scale $d_{x^2 - y^2}$-wave SC pairing order between Cu-Cu and O-O. While all parametrizations of the model display AF and SC phases, the decay of AF order with doping is too slow compared to the experimental phase diagram, and further, coexistence of AF and SC orders occurs in all parameter sets. Our work highlights the importance of the oxygen degrees of freedom in the study of atomic-scale SC orders, as well as the necessity of re-evaluating current parametrizations of the three-band Hubbard model.

Jan 14, 20201 citation

Studies of dynamic critical behaviour in YBa2Cu3O7−δ single crystals

Han Shun-hui, Björn Lundqvist, Yuri Eltsev +1 more

Physica C SuperconductivityNov 1, 20000 citations

Phase diagram of the three-band half-filled Cu-O two-leg ladder

Sootaek Lee, John Bradley Marston, John Ove Fjærestad

We determine the phase diagram of the half-filled two-leg ladder both at weak and strong coupling, taking into account the Cu ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ and the O ${p}_{x}$ and ${p}_{y}$ orbitals. At weak coupling, renormalization group flows are interpreted with the use of bosonization. Two different models with and without outer oxygen orbitals are examined. For physical parameters, and in the absence of the outer oxygen orbitals, the D-Mott phase arises; a dimerized phase appears when the outer oxygen atoms are included. We show that the circulating current phase that preserves translational symmetry does not appear at weak coupling. In the opposite strong-coupling atomic limit the model is purely electrostatic and the ground states may be found by simple energy minimization. The phase diagram so obtained is compared to the weak-coupling one.We determine the phase diagram of the half-filled two-leg ladder both at weak and strong coupling, taking into account the Cu ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ and the O ${p}_{x}$ and ${p}_{y}$ orbitals. At weak coupling, renormalization group flows are interpreted with the use of bosonization. Two different models with and without outer oxygen orbitals are examined. For physical parameters, and in the absence of the outer oxygen orbitals, the D-Mott phase arises; a dimerized phase appears when the outer oxygen atoms are included. We show that the circulating current phase that preserves translational symmetry does not appear at weak coupling. In the opposite strong-coupling atomic limit the model is purely electrostatic and the ground states may be found by simple energy minimization. The phase diagram so obtained is compared to the weak-coupling one.

arXiv:cond-mat/0503380Physical Review BAug 18, 200512 citations

Phase Diagram for Mixed-Parity Superconductors

Paola Gentile, Gaetano Annunziata, Mario Cuoco +2 more

Journal of Superconductivity and Novel MagnetismSep 21, 20100 citations

Universality class of the structural phase transition in the normal phase of cuprate superconductors

M. N. Najafi, Ali Tavana

The tetragonal-orthorhombic structural phase transition of oxygen atoms in the basal plane of YBa_{2}Cu_{3}O_{6+δ} high-T_{C} cuprate superconductors is studied numerically. By mapping the system onto the asymmetric next-nearest-neighbor Ising model, we characterize this phase transition. Results indicate the degrees of critical behavior. We show that this phase transition occurs at the temperature T_{C}≃0.148eV in the thermodynamic limit. By analyzing the critical exponents, it is found that this universality class displays some common features, with the two-dimensional three-state Potts model universality class, although the possibility of other universality classes cannot be ruled out. Conformal invariance at T=T_{c} is investigated using the Schramm-Loewner evolution (SLE) technique, and it is found that the SLE diffusivity parameter for this system is 3.34±0.01.The tetragonal-orthorhombic structural phase transition of oxygen atoms in the basal plane of YBa_{2}Cu_{3}O_{6+δ} high-T_{C} cuprate superconductors is studied numerically. By mapping the system onto the asymmetric next-nearest-neighbor Ising model, we characterize this phase transition. Results indicate the degrees of critical behavior. We show that this phase transition occurs at the temperature T_{C}≃0.148eV in the thermodynamic limit. By analyzing the critical exponents, it is found that this universality class displays some common features, with the two-dimensional three-state Potts model universality class, although the possibility of other universality classes cannot be ruled out. Conformal invariance at T=T_{c} is investigated using the Schramm-Loewner evolution (SLE) technique, and it is found that the SLE diffusivity parameter for this system is 3.34±0.01.

Physical review. EAug 8, 20165 citations

p_{x (y)}

[or

d_{xz (yz)}

]-symmetry modulation of the pair density on the Cu-O bonds within the larger scale

d_{x^2 - y^2}

-wave SC pairing order between Cu-Cu and O-O. While all parametrizations of the model display AF and SC phases, the decay of AF order with doping is too slow compared to the experimental phase diagram, and further, coexistence of AF and SC orders occurs in all parameter sets. Our work highlights the importance of the oxygen degrees of freedom in the study of atomic-scale SC orders, as well as the necessity of re-evaluating current parametrizations of the three-band Hubbard model.

We determine the phase diagram of the half-filled two-leg ladder both at weak and strong coupling, taking into account the Cu ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ and the O

{p}_{x}

and

{p}_{y}

orbitals. At weak coupling, renormalization group flows are interpreted with the use of bosonization. Two different models with and without outer oxygen orbitals are examined. For physical parameters, and in the absence of the outer oxygen orbitals, the D-Mott phase arises; a dimerized phase appears when the outer oxygen atoms are included. We show that the circulating current phase that preserves translational symmetry does not appear at weak coupling. In the opposite strong-coupling atomic limit the model is purely electrostatic and the ground states may be found by simple energy minimization. The phase diagram so obtained is compared to the weak-coupling one.