Novel electronic and phonon-related properties of the newly discovered silicide superconductor Li ₂ IrSi ₃

Abstract

By means of first-principles calculations, we investigate the electronic structure, lattice dynamics, and electron-phonon coupling of the newly discovered silicide superconductor Li2IrSi3. The band structure shows obvious three-dimensional character, and the number of hole pockets around the center of the Brillouin zone depends on whether spin-orbit coupling is taken into consideration. For the phonon-related properties, a phononic-crystal-like behavior with a frequency gap in the range 400 cm −1 < ω < 411 cm −1 is discovered, which makes Li2IrSi3 a good candidate for controlling the propagation of phonons. The electron-phonon coupling constant λ equals 0.52, and the estimated superconducting transition temperature Tc 4.1 K is close to its experimental value, suggesting that Li2IrSi3 is a weak-coupling phonon-mediated superconductor.

Structural, elastic, and electronic properties of recently discovered ternary silicide superconductor Li2IrSi3: Anab-initiostudy

“…The Θ D value is estimated to be 486 K by using the phonon contribution to the low temperature specific heat derived from experimental data of C P . [2] Very recently, the theoretical estimate of Θ D from lattice dynamical calculations yielded a value of 488 K, [25] exactly equal to the value estimated from the theoretical elastic moduli in this study. All these suggest that our calculations are reliable.…”

Pressure Dependence of Superconducting Behavior of 4d and 5d Transition Metal Compounds CaRh2 and CaIr2

“…It has been discovered that some of Rh- and Ir-based compounds are superconductors, e.g., Zr 2 Rh, Rh 17 S 15 , Lu 3 Rh 4 Ge 13 , Y 3 Rh 4 Ge 13 , SrRh 2 , BaRh 2 , Ca 3 It 4 Ge 4 , IrGe, Li 2 IrSi 3 , − La 3 Ir 2 Ge 2, and Ce 3 Ir 2 Ge 2 . The Ir/Rh compounds of Ir 0.95– x Rh x Te 2 and Ir 0.58 Rh 0.36 Se 2 indicated T c values of 4.7–2.4 and 9.6 K, respectively. , Recently, a superconducting phase in CaIr 2 with a high T c value of 5.8 K at ambient pressure was discovered .…”

Ab initio investigation of spin orbit coupling effect on the physical properties of IrGe superconductor

“…Thus, SOC is anticipated to play a significant role in the transition from the normal state to the superconducting state in Mg 10 Ir 19 B 16 due to the heavy mass of Ir atom. Two experimental groups [6,7] have reported that Li 2 IrSi 3 displays type-II superconductivity with a superconducting transition temperature T c of 3.8 K. Two theoretical calculations [8,9] made on this superconductor reveal that Ir 5d states make the main contribution to the electronic density of states close to the Fermi energy. In particular, Lu and co-workers [9] have concluded that Li 2 IrSi 3 is a weak-coupling phonon-mediated superconductor.…”

“…Two experimental groups [6,7] have reported that Li 2 IrSi 3 displays type-II superconductivity with a superconducting transition temperature T c of 3.8 K. Two theoretical calculations [8,9] made on this superconductor reveal that Ir 5d states make the main contribution to the electronic density of states close to the Fermi energy. In particular, Lu and co-workers [9] have concluded that Li 2 IrSi 3 is a weak-coupling phonon-mediated superconductor. The existence of bulk superconducting transition with T c = 5.8 K for the pyrochlore lattice superconductor CaIr 2 has been reported and the properties of this superconductor have been elucidated trough magnetization [10].…”