• Corpus ID: 119449205

Van Hove singularities, chemical pressure and phonons: an angle-resolved photoemission study of KFe$_2$As$_2$ and CsFe$_2$As$_2$

  title={Van Hove singularities, chemical pressure and phonons: an angle-resolved photoemission study of KFe\$\_2\$As\$\_2\$ and CsFe\$\_2\$As\$\_2\$},
  author={Pierre Richard and Ambroise van Roekeghem and X. Shi and Priyanka Seth and Baijiang Lv and T. K. Kim and X.-H. Chen and Silke Biermann and Hong Ding},
  journal={arXiv: Superconductivity},
We report an angle-resolved photoemission spectroscopy (ARPES) study of KFe$_2$As$_2$ and CsFe$_2$As$_2$, revealing the existence of a van Hove singularity affecting the electronic properties. As a result of chemical pressure, we find a stronger three-dimensionality in KFe$_2$As$_2$ than in CsFe$_2$As$_2$, notably for the 3$d_{z^2}$ states responsible for the small three-dimensional hole-like Fermi surface pocket reported by quantum oscillations. Supported by first-principles calculations, our… 

Figures from this paper


Fermi surface in KFe2As2determined via de Haas–van Alphen oscillation measurements
We have completely determined the Fermi surface in KFe$_2$As$_2$ via de Haas-van Alphen (dHvA) measurements. Fundamental frequencies $\epsilon$, $\alpha$, $\zeta$, and $\beta$ are observed in
Microscopic nature of correlations in multi-orbital AFe2As2 (A=K, Rb, Cs): Hund's coupling versus Coulomb repulsion
We investigate via LDA+DMFT (local density approximation combined with dynamical mean field theory) the manifestation of correlation effects in a wide range of binding energies in the hole-doped
Two distinct superconducting states in KFe 2 As 2 under high pressure
We report measurements of ac magnetic susceptibility $\chi_{ac}$ and de Haas-van Alphen (dHvA) oscillations in KFe$_2$As$_2$ under high pressure up to 24.7 kbar. The pressure dependence of the
Evolution of quasiparticle excitations with enhanced electron correlations in superconducting A Fe 2 As 2 ( A = K , Rb, and Cs)
In the heavily hole-doped iron-based superconductors $A$Fe$_2$As$_2$ ($A=$ K, Rb, and Cs), the electron effective mass increases rapidly with alkali-ion radius. To study how the mass enhancement
Anomalous impurity effects in the iron-based superconductor KFe2As2
High-quality K(Fe$_{1-x}$Co$_x$)$_2$As$_2$ single crystals have been grown by using KAs flux method. Instead of increasing the superconducting transition temperature $T_{\rm c}$ through electron
Nodal gap in iron-based superconductor CsFe2As2 probed by quasiparticle heat transport
The thermal conductivity of iron-based superconductor CsFe$_2$As$_2$ single crystal ($T_c =$ 1.81 K) was measured down to 50 mK. A significant residual linear term $\kappa_0/T$ = 1.27 mW K$^{-2}$
Pressure dependence of phonon modes across the tetragonal to collapsed-tetragonal phase transition in CaFe 2 As 2
The pressure dependence of a large number of phonon modes in ${\text{CaFe}}_{2}{\text{As}}_{2}$ with energies covering the full range of the phonon spectrum has been studied using inelastic x-ray and
Angle-resolved spectroscopy study of Ni-based superconductor SrNi 2 As 2
We performed an angle-resolved photoemission spectroscopy study of the Ni-based superconductor SrNi$_2$As$_2$. Electron and hole Fermi surface pockets are observed, but their different shapes and
Electronic structure and de Haas-van Alphen frequencies in KFe 2 As 2 within LDA+DMFT
Recent density functional theory (DFT) calculations for KFe2As2 have been shown to be insufficient to satisfactorily describe angle-resolved photoemission (ARPES) measurements as well as observed de
Electronic structure in a one-Fe Brillouin zone of the iron pnictide superconductors CsFe 2 As 2 and RbFe 2 As 2
The multiband nature of iron-pnictide superconductors is one of the keys to the understanding of their intriguing behavior. The electronic and magnetic properties heavily rely on the multiband