Band crossover and magnetic phase diagram of high-Tc superconducting compound Ba2CuO4-δ

Abstract

We present the influences of electronic and magnetic correlations and doping evolution on the groundstate properties of recently discovered superconductor Ba${}_2$CuO${}_{4-\delta }$ by utilizing the Kotliar-Ruckenstein slave boson method. Starting with an effective two-orbital Hubbard model (Scalapino {\it et al.} Phys. Rev. {\bf B 99}, 224515 (2019)), we demonstrate that with increasing doping concentration, the paramagnetic (PM) system evolves from two-band character to single-band ones around the electron filling n=2.5, with the band nature of the $d_{3z^2-r^2}$ and $d_{x^2-y^2}$ orbitals to the $d_{x^2-y^2}$ orbital, slightly affected when the electronic correlation U varies from 2 to 4 eV. Considering the magnetic correlations, the system displays one antiferromagnetically metallic (AFM) phase in $2<n<2.16$ and a PM phase in $n>2.16$ at U=2 eV, or two AFM phases in $2<n<2.57$ and $2.76<n<3$, and a PM phase in $2.57<n<2.76$ respectively, at U=4 eV. Our results show that near realistic superconducting state around n=2.6 the intermediate correlated Ba${}_2$CuO${}_{3,2}$ should be single band character, and the s-wave superconducting pairing strength becomes significant when U$>$2 eV, and crosses over to d-wave when U$>$2.2 eV.

9 pages, 10 figures

References in corpus (4)

• Orbital selective Mott transition in multi-band systems: slave-spin representation and dynamical mean-field theory
• Rotationally-invariant slave-boson formalism and momentum dependence of the quasiparticle weight
• Electronic structures of quasi-one-dimensional cuprate superconductors Ba${}_2$CuO${}_{3+\delta }$
• Orbital Symmetry and Orbital Excitations in High-$T_c$ Superconductors

Cited by in corpus (1)

• Lattice Quantum Geometry Controlling 118 K Multigap Superconductivity in Heavily Overdoped CuBa2Ca3Cu4O10+d