Pressure effects on the unconventional superconductivity of the noncentrosymmetric LaNiC2

Abstract

The unconventional superconductivity in the noncentrosymmetric LaNiC${}_2$, and its evolution with pressure, is analyzed basing on the {\it ab initio} computations and the full Eliashberg formalism. First principles calculations of the electronic structure, phonons and the electron-phonon coupling are reported in the pressure range 0-15 GPa. The thermodynamic properties of the superconducting state were determined numerically solving the Eliashberg equations. We found that already at $p=0$ GPa, the superconducting parameters deviate from the BCS-type, and a large value of the Coulomb pseudopotential ${\mu }^{\star }=0.22$ is required to get the critical temperature $T_c=2.8$~K consistent with experiment. If such ${\mu }^{\star }$ is used, the Eliashberg formalism reproduces also the experimentally observed values of the superconducting order parameter, the electronic specific heat jump at the critical temperature, and the change of the London penetration depth with temperature. This shows, that deviation of the above-mentioned parameters from the BCS predictions do not prejudge on the triplet or multiple gap nature of the superconductivity in this compound. Under the external pressure, calculations predict continuous increase of the electron-phonon coupling constant in the whole pressure range 0-15~GPa, consistent with the experimentally observed increase in $T_c$ for the pressure range 0-4~GPa, but inconsistent with the drop of $T_c$ above 4~GPa and the disappearance of the superconductivity above 7~GPa, reported experimentally. The disappearance of superconductivity may be accounted for by increasing the ${\mu }^{\star }$ to 0.36 at 7~GPa, which supports the hypothesis of the formation of a new high-pressure electronic phase, which competes with the superconductivity.

arXiv comment15 pages, 13 figures, to be published in Phys. Rev. B

References in corpus (23)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Heavy fermion superconductivity and magnetic order in non-centrosymmetric $CeP{t}_{3}Si$
• Electron-phonon interactions and related physical properties of metals from linear-response theory
• Superconductivity and spin-orbit coupling in non-centrosymmetric materials: a review
• S-wave/spin-triplet order in superconductors without inversion symmetry: Li${}_2$Pd${}_3$B and Li${}_2$Pt${}_3$B
• First-Principles Calculation of the Superconducting Transition in MgB2 within the Anisotropic Eliashberg Formalism
• Evidence for time-reversal symmetry breaking in the non-centrosymmetric superconductor LaNiC${}_2$
• Superconductivity in metal rich Li-Pd-B ternary Boride
• Spin Triplet Superconducting State due to Broken Inversion Symmetry in Li_2Pt_3B
• Crystal Symmetry, Electron-Phonon Coupling, and Superconducting Tendencies in Li${}_2$Pd${}_3$B and Li${}_2$Pt${}_3$B
• Evidence for two-gap superconductivity in the non-centrosymmetric compound LaNiC${}_2$
• Multigap superconductivity in sesquicarbides La${}_2$C${}_3$ and Y${}_2$C${}_3$
• Relativistic analysis of the pairing symmetry of the noncentrosymmetric superconductor LaNiC${}_2$
• Non-BCS thermodynamic properties of H2S superconductor
• Superconductivity in Mg10Ir19B16
• High-temperature study of superconducting hydrogen and deuterium sulfide
• The electronic structure of {\em R}NiC${}_2$ intermetallic compounds
• Superconductivity of Ta34Nb33Hf8Zr14Ti11 high entropy alloy from first principles calculations
• Nodal gap structure in the noncentrosymmetric superconductor LaNiC2 from magnetic-penetration-depth measurements
• Strong electron-phonon coupling in the rare-earth carbide superconductor La2C3
• Electron-phonon superconductivity in non-centrosymmetric LaNiC${}_2$: first principles calculations
• Pressure effects on the superconductivity of HfPd2Al Heusler compound: Experimental and theoretical study
• Anisotropy of the gap parameter in the hole-doped cuprates

Cited by in corpus (19)

• Magnetism and charge density waves in RNiC${}_2$ (R = Ce, Pr, Nd)
• Isotope effect in superconducting lanthanum hydride under high compression
• NbIr${}_2$B${}_2$ and TaIr${}_2$B${}_2$ -- new low symmetry noncentrosymmetric superconductors with strong spin orbit coupling
• Extended phase diagram of RNiC2 family: Linear scaling of the Peierls temperature
• Dirac lines and loop at the Fermi level in the Time-Reversal Symmetry Breaking Superconductor LaNiGa${}_2$
• Exact factorization-based density functional theory of electron-phonon systems
• Charge density wave and large non-saturating magnetoresistance in YNiC${}_2$ and LuNiC${}_2$
• Unconventional superconductivity and an ambient-pressure magnetic quantum critical point in single-crystal LaNiC${}_2$
• Superconducting properties of MoTe${}_2$ from the $abinitio$ anisotropic Migdal-Eliashberg theory
• Electronic structure, electron-phonon coupling and superconductivity in noncentrosymmetric ThCoC2 from ab initio calculations
• The Thermodynamics and the Inverse Isotope Effect of superconducting PdH and PdD under pressure
• Pressure effects on the electronic structure, phonons, and superconductivity of noncentrosymmetric ThCoC2
• Fermi surface segmentation in the helical state of a Rashba superconductor
• Correlation between charge density waves and antiferromagnetism in Nd${}_{1-x}$Gd${}_x$NiC${}_2$ solid solution
• Crossover from charge density wave stabilized antiferromagnetism to superconductivity in Nd${}_{1-x}$La${}_x$NiC${}_2$ compounds
• Unbalanced superconductivity induced by the constant electron-phonon coupling on a square lattice
• Pressure induced superconducting dome in LaNiGa2
• The effect of Ni doping on the electronic structure and superconductivity in the noncentrosymmetric ThCoC2
• Magnetic excitations in the helical Rashba superconductor