VietNam 2013 

IXth Rencontres du Vietnam
Quy-Nhon, August 4-10, 2013


 Nanophysics: from fundamentals to applications

(the return)


Wednesday 7

› 14:20 - 14:40 (20min)
Topological superconductors, two case studies: CuxBi2Se3 and YPtBi
Tran Van Bay  1, 2, *@  , Takashi Naka  3@  , Yingkai Huang  1@  , Huib Luigjes  1@  , Mark S. Golden  1@  , Anne De Visser  1@  
1 : Institute of Physics, University of Amsterdam  (IoP, UvA)  -  Website
Science Park 904, 1098 XH Amsterdam -  Netherlands
2 : Quy Nhon University  (QNhU)
170 An Duong Vuong, Quynhon city, Binhdinh province -  Vietnam
3 : National Institute for Materials Science  (NIMS)
Advanced Key Technologies Division, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047 -  Japan
* : Corresponding author

Recently, topological insulators have sparked a wide research interest because they offer a new playground for the realization of novel states of quantum matter. The concept of topological insulators can also be applied to superconductors due to the direct analogy between topological band theory and superconductivity. Here we present two case studies of (candidate) topological superconductors: (i) the Cu intercalated topological insulator material Bi2Se3 (Tc = 3.5 K) and (ii) the non-centrosymmetric half Heusler compound YPtBi (Tc = 0.77 K). Single crystalline samples were synthesized and the superconducting parameters were determined by transport and magnetic measurements. We focus on the response to mechanical pressure of the superconducting phase up to 2.5 GPa. In both cases the upper critical field Bc2(T) curves collapse onto a single curve that is at odds with the standard behavior for a weak-coupling, orbital-limited, spin-singlet superconductor. The absence of paramagnetic limiting, an electron mean free path in excess of the superconducting coherence length, and the unusual temperature variation of Bc2 point to an odd-parity component in the superconducting order parameter [1,2], in accordance with theoretical predictions.


[1, 2] Bay et al., PRL 108, 057001; PRB 86, 064515 (2012).

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