Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn$_{1-x}$In$_x$Te for x $\geq$ 0.10

M. P. Smylie; H. Claus; W. -K. Kwok; E. R. Louden; M. R. Eskildsen; A. S. Sefat; R. D. Zhong; J. Schneeloch; G. D. Gu; E. Bokari; P. M. Niraula; A. Kayani; C. D. Dewhurst; A. Snezhko; U. Welp

doi:10.1103/physrevb.97.024511

arXiv · 1711.09862

Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn$_{1-x}$In$_x$Te for x $\geq$ 0.10

M. P. Smylie·H. Claus·W. -K. Kwok·E. R. Louden·M. R. Eskildsen·A. S. Sefat·R. D. Zhong·J. Schneeloch·G. D. Gu·E. Bokari·P. M. Niraula·A. Kayani·C. D. Dewhurst·A. Snezhko·U. Welp

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Abstract

The temperature dependence of the London penetration depth $Δλ(T)$ in the superconducting doped topological crystalline insulator Sn$_{1-x}$In$_x$Te was measured down to 450 mK for two different doping levels, x $\approx$ 0.45 (optimally doped) and x $\approx$ 0.10 (underdoped), bookending the range of cubic phase in the compound. The results indicate no deviation from fully gapped BCS-like behavior, eliminating several candidate unconventional gap structures. Critical field values below 1 K and other superconducting parameters are also presented. The introduction of disorder by repeated particle irradiation with 5 MeV protons does not enhance $T_c$, indicating that ferroelectric interactions do not compete with superconductivity.

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M. P. Smylie, H. Claus, W. -K. Kwok, E. R. Louden, M. R. Eskildsen, A. S. Sefat, R. D. Zhong, J. Schneeloch, G. D. Gu, E. Bokari, P. M. Niraula, A. Kayani, C. D. Dewhurst, A. Snezhko, U. Welp. 2017-11-27. Superconductivity, pairing symmetry, and disorder in the doped topological insulator Sn$_{1-x}$In$_x$Te for x $\geq$ 0.10. https://doi.org/10.1103/physrevb.97.024511

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