2014/10/08 by Leena Aggarwal, Abhishek Gaurav, Gohil S. Thakur +3 · 1 citation
Physics and Astronomy · #cond-mat.supr-con
paper · pdf · doi:10.1038/nmat4455
published as Nature Materials 2016 · includes supplementary materials at the end
arxiv created 2014/10/08 · arxiv updated 2016/02/29
Since the three dimensional (3D) Dirac semi-metal Cd3As2 exists close to topological phase boundaries, in principle it should be possible to drive it into exotic new phases, like topological superconductors, by breaking certain symmetries. Here we show that the mesoscopic point-contacts between silver (Ag) and Cd3As2 exhibit superconductivity up to a critical temperature (onset) of 6 K while neither Cd3As2 nor Ag are superconductors. A gap amplitude of 6.5 meV is measured spectroscopically in this phase that varies weakly with temperature and survives up to a remarkably high temperature of 13 K indicating the presence of a robust normal-state pseudogap. The observations indicate the emergence of a new unconventional superconducting phase that exists only in a quantum mechanically confined region under a point-contact between a Dirac semi-metal and a normal metal.