Strong enhancement of conventional superconductivity near a quantum critical point of (Ca,Sr)_3Ir_4Sn_13

Abstract

Competing electronic states are found in the large majority of unconventional superconductors, including high-Tc cuprates, iron based superconductors and many heavy fermion systems. The complex interplay is reflected in phase diagrams as a function of doping or other tuning parameters involving besides superconducting other phases (often magnetic) and quantum critical points. Superconductivity is also found in the vicinity of charge density wave (CDW) order in phase diagrams reminiscent of superconductivity mediated by magnetic fluctuations. There is however less knowledge about the interplay of superconductivity and CDW compared to the magnetic analogon. Here we report about microscopic studies by muon spin rotation as a function of pressure of the Ca_3Ir_4Sn_13 and Sr_3Ir_4Sn_13 cubic compounds, which display superconductivity and a structural phase transition associated with the formation of a CDW. We find a strong enhancement of the superfluid density and of the coupling strength above a pressure of about 1.6 GPa giving direct evidence of the presence of a quantum critical point separating a superconducting phase coexisting with CDW from a pure superconducting phase. The superconducting order parameter in both phases are found to have the same s-wave symmetry. In spite of the conventional phonon-mediated BCS character of this compound, the dependence of the effective superfluid density on the critical temperature puts this system in the "Uemura" plot close to unconventional superconductors.

accepted for publication Phys. Rev. B

References in corpus (16)

• High-temperature superconductivity in iron-based materials
• Direct observation of competition between superconductivity and charge density wave order in YBa2Cu3Oy
• Theory of Intertwined Orders in High Temperature Superconductors
• Quantum criticality
• A Sharp Peak of the Zero-Temperature Penetration Depth at Optimal Composition in BaFe2(As1-xPx)2
• Connection between charge-density-wave order and charge transport in the cuprate superconductors
• Muon-spin rotation studies of SmFeAsO_0.85 and NdFeAsO_0.85 superconductors
• Condensation, excitation, pairing, and superfluid density in high-$T_c$ superconductors: magnetic resonance mode as a roton analogue and a possible spin-mediated pairing
• Ambient Pressure Structural Quantum Critical Point in the Phase Diagram of (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$
• Ca${}_3$Ir${}_4$Sn${}_{13}$: A weakly correlated nodeless superconductor
• Strong Coupling Superconductivity in the Vicinity of the Structural Quantum Critical Point in (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$
• Sudden reversal in the pressure dependence of Tc in the iron-based superconductor CsFe2As2: A possible link between inelastic scattering and pairing symmetry
• Crystal structure and phonon softening in Ca3Ir4Sn13
• Unconventional charge-density wave in Sr3Ir4Sn13 cubic superconductor revealed by optical spectroscopy study
• Superconducting and magnetic properties of Sr3Ir4Sn13
• Strong pressure dependence of the magnetic penetration depth in single crystals of the heavy fermion superconductor CeCoIn5 studied by muon spin rotation

Cited by in corpus (22)

• Strong Coupling Superconductivity in the Vicinity of the Structural Quantum Critical Point in (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$
• Fully gapped superconductivity in the topological superconductor beta-PdBi2
• Evidence of a structural quantum critical point in (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$ from a lattice dynamics study
• Second-order Structural Transition in Superconductor La${}_3$Co${}_4$Sn${}_{13}$
• Study of Nb${}_{0.18}$Re${}_{0.82}$ non-centrosymmetric superconductor in the normal and superconducting states
• Soft phonon modes in the vicinity of the structural quantum critical point
• Candidate Elastic Quantum Critical Point in LaCu${}_{6-x}$Au${}_x$
• Possible unconventional pairing in $(\text{Ca,Sr}{)}_3(\text{Ir,Rh}{)}_4{\text{Sn}}_{13}$ superconductors revealed by controlling disorder
• Nodeless superconductivity and the peak effect in the quasi-skutterudites ${\mathrm{Lu}}_3{\mathrm{Os}}_4{\mathrm{Ge}}_{13}$ and ${\mathrm{Y}}_3{\mathrm{Ru}}_4{\mathrm{Ge}}_{13}$
• Optical spectroscopy study of charge density wave order in Sr${}_3$Rh${}_4$Sn${}_{13}$ and (Sr${}_{0.5}$Ca${}_{0.5}$)${}_3$Rh${}_4$Sn${}_{13}$
• Pressure effects on the structural and superconducting transitions in La3Co4Sn13
• Structural phase transition, precursory electronic anomaly and strong-coupling superconductivity in quasi-skutterudite (Sr${}_{1-x}$Ca${}_x$)${}_3$Ir${}_4$Sn${}_{13}$ and Ca${}_3$Rh${}_4$Sn${}_{13}$
• Experimental Determination of the Fermi Surface of Sr3Ir4Sn13
• Peak in the critical current density in (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$ tuned towards the structural quantum critical point
• Possible quantum fluctuations in the vicinity of the quantum critical point of $(\mathbf{Sr},\mathbf{Ca}{)}_3\mathbf{I}{\mathbf{r}}_4\mathbf{S}{\mathbf{n}}_{13}$ revealed by high-energy X-ray diffraction study
• Possible structural quantum criticality tuned by rare-earth ion substitution in infinite-layer nickelates
• Interplay between charge density wave and superconductivity in multi-band systems with inter-band Coulomb interaction
• Time-reversal symmetry breaking in superconducting low-carrier-density quasi-skutterudite Lu3Os4Ge13
• Broken time-reversal symmetry in cubic skutterudite-like superconductor Y${}_3$Ru${}_4$Ge${}_{13}$
• Tuning the structural and antiferromagnetic phase transitions in UCr${}_2$Si${}_2$: hydrostatic pressure and chemical substitution
• Evidence of unconventional pairing in the quasi two-dimensional CuIr${}_2$Te${}_4$ superconductor
• Reaching Quantum Critical Point by Adding Non-magnetic Disorder in Single Crystals of Superconductor $({\text{Ca}}_x{\text{Sr}}_{1-x}{)}_3{\text{Rh}}_4{\text{Sn}}_{13}$