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arXiv · 1512.02459

Nodeless superconductivity in noncentrosymmetric PbTaSe$_2$ single crystals

G. M. Pang·M. Smidman·L. X. Zhao·Y. F. Wang·Z. F. Weng·L. Q. Che·Y. Chen·X. Lu·G. F. Chen·H. Q. Yuan
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Abstract

We report an investigation of the superconducting order parameter of the noncentrosymmetric compound PbTaSe$_2$, which is believed to have a topologically nontrivial band structure. Precise measurements of the London penetration depth $\Delta\lambda(T)$ obtained using a tunnel diode oscillator (TDO) based method show an exponential temperature dependence at $T\ll T_c$, suggesting a nodeless superconducting gap structure. A single band s-wave model well describes the corresponding normalized superfluid density, with a gap magnitude of $\Delta(0)=1.85T_c$. This is very close to the value of $1.76T_c$ for weak-coupling BCS superconductors, indicating conventional fully-gapped superconductivity in PbTaSe$_2$.

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G. M. Pang, M. Smidman, L. X. Zhao, Y. F. Wang, Z. F. Weng, L. Q. Che, Y. Chen, X. Lu, G. F. Chen, H. Q. Yuan. 2015-12-08. Nodeless superconductivity in noncentrosymmetric PbTaSe$_2$ single crystals. https://doi.org/10.1103/physrevb.93.060506

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