R. D. Zhong

Optimizing the superconducting transition temperature and upper critical field of Sn1-xInxTe

Sn(1-x)In(x)Te is a possible candidate for topological superconductivity. Previous work has shown that substitution of In for Sn in the topological crystalline insulator SnTe results in superconductivity, with the transition temperature, Tc, growing with In concentration. We have performed a systematic investigation of Sn(1-x)In(x)Te for a broad range of x, synthesizing single crystals (by a modified floating zone method) as well as polycrystalline samples. The samples have been characterized by x-ray diffraction, resistivity, and magnetization. For the single crystals, the maximum Tc is obtained at x=0.45 with a value of of 4.5 K, as determined by the onset of diamagnetism.

Phonon anomalies in some iron telluride materials

In this paper, the detailed temperature dependence of the infrared-active mode in Fe1.03Te (TN ≃ 68 K) and Fe1.13Te (TN ≃ 56 K) has been examined, and the position, width, strength, and asymmetry parameter have been determined using an asymmetric Fano profile superimposed on an electronic background. In both materials the frequency of the mode increases as the temperature is reduced; however, there is also a slight asymmetry in the line shape, indicating that the mode is coupled to either spin or charge excitations. Below TN there is an anomalous decrease in frequency, and the mode shows little temperature dependence, at the same time becoming more symmetric, suggesting a reduction in spin- or electron-phonon coupling. The frequency of the infrared-active mode and the magnitude of the shift below TN are predicted reasonably well by first-principles calculations; however, the predicted splitting of the mode is not observed. In superconducting FeTe0.55Se0.45 (Tc ≃ 14 K) the infrared-active Eu mode displays asymmetric line shape at all temperatures, which is most pronounced between 100 – 200 K, indicating the presence of either spin- or electron-phonon coupling, which may be a necessary prerequisite for superconductivity in this class of materials.

Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn1-xInxTe for x≥0.10 SUPERCONDUCTIVITY, PAIRING SYMMETRY, and .. M. P. SMYLIE et al.

The temperature dependence of the London penetration depth

Substitution of Ni for Fe in superconducting Fe0.98Te0.5Se0.5 depresses the normal-state conductivity but not the magnetic spectral weight

\Delta\lambda(T)

Dependence of superconductivity in CuxBi2Se3 on quenching conditions

in the superconducting doped topological crystalline insulator Sn

Surface-state-dominated transport in crystals of the topological crystalline insulator In-doped Pb1-xSnxTe

_{1-x}

Low-energy phonons and superconductivity in Sn 0.8 In 0.2 Te

In

Suppression of the antiferromagnetic order when approaching the superconducting state in a phase-separated crystal of KxFe2-ySe2

_x

Dependence of superconductivity in Cu{x}Bi{2}Se{3} on quenching conditions

Te was measured down to 450 mK for two different doping levels, x

Dependence of superconductivity inCuxBi2Se3on quenching conditions

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