Subtle Structural Anomaly under Compression in Line-Nodal CaSb${}_2$

Abstract

We report X-ray diffraction patterns and calculated electronic band structures of the Dirac line-nodal material CaSb${}_2$ under pressure. Its superconducting transition temperature ($T_{\mathrm{c}}=1.7$ K) increases under pressure and reaches a maximum at 3.4 K at around 3 GPa. We observed subtle anomalies in lattice parameters accompanied by a jump in bulk modulus without any change in crystal symmetry at around 3 GPa. First-principles calculations revealed that the distorted lattice of Sb(1) site deforms in the pressure range of 0-3 GPa. Those results suggest the existence of a first-order structural transition and arouse expectations for unusual phononic properties affecting the superconducting state. The calculated pressure dependence of the electronic density of states (DOS) confirms that it is not the change in the DOS that governs the variations in $T_{\mathrm{c}}$.

8 pages, 7 figures

References in corpus (22)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• WannierTools: An open-source software package for novel topological materials
• Dirac Cone Protected by Non-Symmorphic Symmetry and 3D Dirac Line Node in ZrSiS
• Topological nodal line semimetals
• Topological Dirac Nodal Lines and Surface Charges in fcc Alkaline Earth Metals
• Long-range Coulomb interaction in nodal-ring semimetals
• Topological transport in Dirac nodal-line semimetals
• Observation of topological nodal-line fermionic phase in GdSbTe
• Thermodynamic Properties and Pressure Effect on the Superconductivity in CaAlSi and SrAlSi
• Quasi-Topological Electromagnetic Response of Line-node Semimetals
• Pressure induced half-collapsed-tetragonal phase in CaKFe${}_4$As${}_4$
• Superconductivity in the nonsymmorphic line-nodal compound CaSb${}_2$
• S-wave Superconductivity in the Dirac Line-nodal Material CaSb2
• Topological piezoelectric effect and parity anomaly in nodal line semimetals
• Peak in the superconducting transition temperature of the nonmagnetic topological line-nodal material CaSb${}_2$ under pressure
• Two-gap to Single-gap Superconducting Transition on a Honeycomb Lattice in Ca${}_{1-x}$Sr${}_x$AlSi
• Quasi-2D Fermi surface of superconducting line-nodal metal CaSb${}_2$
• Superconductivity and Quantum Oscillations in Single Crystals of the Compensated Semimetal CaSb${}_2$
• Nodeless superconductivity in the topological nodal-line semimetal CaSb2
• Fermiology of a topological line-nodal compound CaSb2 and its implication to superconductivity: angle-resolved photoemission study
• Pressure evolution of the normal- and superconducting-state properties of the line-nodal material CaSb${}_2$ revealed by ${}^{123}$Sb nuclear quadrupole resonance