Soft phonon modes in the vicinity of the structural quantum critical point

Abstract

The quasi-skutterudite superconductors $A_3{T}_4$Sn${}_{13}$ ($A$=Sr, Ca; $T$=Ir, Rh, Co) are highly tunable featuring a structural quantum critical point. We construct a temperature-lattice constant phase diagram for these isovalent compounds, establishing Ca${}_3$Rh${}_4$Sn${}_{13}$ and Ca${}_3$Co${}_4$Sn${}_{13}$ as members close to and far away from the structural quantum critical point, respectively. Deconvolution of the lattice specific heat and the electrical resistivity provide an approximate phonon density of states $F(\omega )$ and the electron-phonon transport coupling function ${\alpha }_{tr}^{2}F(\omega )$ for Ca${}_3$Rh${}_4$Sn${}_{13}$ and Ca${}_3$Co${}_4$Sn${}_{13}$, enabling us to investigate the influence of the structural quantum critical point. Our results support the scenario of phonon softening close to the structural quantum critical point, and explain the enhancement of the coupling strength on approaching structural instability.

arXiv comment6 pages, 4 figures. Accepted by Phys. Rev. B

References in corpus (28)

• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Structural quantum criticality and superconductivity in iron-based superconductor Ba(Fe1-xCox)2As2
• Superconductivity Induced by Bond Breaking in the Triangular Lattice of IrTe2
• Pressure-induced and Composition-induced Structural Quantum Phase Transition in the Cubic Superconductor (Sr/Ca)_3Ir_4Sn_{13}
• Structural phase transition in IrTe${}_2$: A combined study of optical spectroscopy and band structure calculations
• Superconductivity mediated by a soft phonon mode: specific heat, resistivity, thermal expansion and magnetization of YB6
• Ambient Pressure Structural Quantum Critical Point in the Phase Diagram of (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$
• Specific heat, magnetic susceptibility, resistivity and thermal expansion of the superconductor ZrB12
• Giant Phonon Softening and Enhancement of Superconductivity by Phosphorus Doping of BaNi2As2
• The emergence of superconductivity in BaNi2(Ge1-xPx)2 at a structural instability
• Superconductivity of La${}_3$Co${}_4$Sn${}_{13}$ and La${}_3$Rh${}_4$Sn${}_{13}$: A comparative study
• 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${}_{13}$
• On the importance of the electron-phonon coupling function on the superconducting transition temperature in dodecaboride superconductors: A comparison of LuB12 with ZrB12
• Phonon density of states, anharmonicity, electron-phonon coupling and possible multigap superconductivity in the clathrate superconductors Ba8Si46 and Ba24Si100: Why is Tc different in these two compounds?
• Electronic structure and phonon instabilities in the vicinity of the structural transition and superconductivity of (Sr,Ca)${}_3$Ir${}_4$Sn${}_{13}$
• Phonon softening near structural transition in BaFe2As2 observed by inelastic x-ray scattering
• Composition-induced structural instability and strong-coupling superconductivity in Au1-xPdxTe2
• Nodeless superconductivity in Ca3Ir4Sn13: evidence from quasiparticle heat transport
• Crystal structure and phonon softening in Ca3Ir4Sn13
• Unconventional charge-density wave in Sr3Ir4Sn13 cubic superconductor revealed by optical spectroscopy study
• Microscopic studies of the normal and superconducting state of Ca3Ir4Sn13
• Strong enhancement of conventional superconductivity near a quantum critical point of (Ca,Sr)_3Ir_4Sn_13
• Superconducting and magnetic properties of Sr3Ir4Sn13
• Superconductivity in the presence of disorder in skutterudite-related La${}_3$Co${}_4$Sn${}_{13}$ and La${}_3$Ru${}_4$Sn${}_{13}$ compounds; electrical transport and magnetic studies
• Second-order Structural Transition in Superconductor La${}_3$Co${}_4$Sn${}_{13}$
• Experimental Determination of the Fermi Surface of Sr3Ir4Sn13
• ${}^{119}$Sn-NMR investigations on superconducting Ca${}_3$Ir${}_4$Sn${}_{13}$: Evidence for multigap superconductivity

Cited by in corpus (7)

• Spin-orbit-coupled ferroelectric superconductivity
• Evidence of a structural quantum critical point in (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$ from a lattice dynamics study
• The effective increase in atomic scale disorder by doping and superconductivity in Ca${}_3$Rh${}_4$Sn${}_{13}$
• 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${}_{13}$
• Peak in the critical current density in (Ca${}_x$Sr${}_{1-x}$)${}_3$Rh${}_4$Sn${}_{13}$ tuned towards the structural quantum critical point
• Magnetic parity violation and parity-time-reversal-symmetric magnets
• Possible structural quantum criticality tuned by rare-earth ion substitution in infinite-layer nickelates