Study on Susceptibilities of Superconductors BaPtSb and BaPtAs with Honeycomb Structure

Abstract

The low-energy electronic properties of the new superconductors BaPtSb and BaPtAs with an ordered honeycomb network are investigated in the normal phase, where the former compound is a candidate for time-reversal symmetry-breaking superconductors. By means of the first-principles calculation, we show that there exist two-dimensional cylinder-like Fermi surfaces around the kz axis and one outer spherelike Fermi surface around the K and K' points in both compounds, which are mainly composed of Pt 5d and Sb 5p/As 4p electrons. We construct low-energy effective models, which are well described by using three bands consisting of two Pt 5d orbitals and one Sb 5p/As 4p orbital. By evaluating susceptibilities using effective models, we find that dominant contributions to those susceptibilities result from the outer spherelike Fermi surface. Whereas out-of-plane fluctuations are enhanced in both compounds in the higher-temperature region, in-plane fluctuations become dominant in the very low-temperature region in BaPtSb owing to a better nesting condition in the k_z=0 plane from the outer spherelike Fermi surface. These fluctuations yield instabilities to ordered states, such as superconductivity, and might be associated with the occurrence of the superconducting state with time-reversal symmetry breaking in BaPtSb.

arXiv comment7 pages, 9 figures

References in corpus (25)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Topological insulators and superconductors
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Wannier90 as a community code: new features and applications
• Topological superconductors: a review
• Colloquium: Topological Band Theory
• Superconducting states of pure and doped graphene
• FermiSurfer: Fermi-surface viewer providing multiple representation schemes
• Competing many-body instabilities and unconventional superconductivity in graphene
• Density waves and Cooper pairing on the honeycomb lattice
• Resonating valence bonds and mean-field d-wave superconductivity in graphite
• Functional renormalization group and variational Monte Carlo studies of the electronic instabilities in graphene near 1/4 doping
• Evidence for Time-Reversal-Symmetry-Broken Superconductivity in Locally Noncentrosymmetric SrPtAs
• Chiral $d$-wave Superconductivity in SrPtAs
• Superconductivity in the Honeycomb-Lattice Pnictide SrPtAs
• Instabilities of interacting electrons on the triangular lattice
• Edge properties of the chiral d-wave superconducting state in doped graphene
• Spin-singlet superconductivity with a full gap in locally non-centrosymmetric SrPtAs
• Low-energy excitations of the Hubbard model on the Kagomé lattice
• Chiral d-wave Superconductivity in a Triangular Surface Lattice Mediated by Long-range Interaction
• Symmetry and Gap Classification of the non-symmorphic SrPtAs
• Superconductivity in Hexagonal BaPtAs: SrPtSb- and YPtAs-type Structures with Ordered Honeycomb Network
• Possibility of chiral $d$-wave state in the hexagonal pnictide superconductor SrPtAs
• Superconductivity in BaPtSb with an Ordered Honeycomb Network
• High-resolution magnetic penetration depth and inhomogeneities in locally noncentrosymmetric SrPtAs

Cited by in corpus (3)

• Spontaneous magnetic field and disorder effects in BaPtAs_1-x_Sb_x_ with honeycomb network
• Highly Uniform Magnetic and Electronic Environment in Non-Centrosymmetric Superconductor LaRhGe${}_3$
• Possible Pairing Symmetry of BaPtAs${}_{1-x}$Sb${}_x$ with an Ordered Honeycomb Network