Centre of Ultra Low Temperature Physics Košice, Institute of Experimental Physics, Slovak Academy of Sciences & Šafárik University Košice, Slovakia
In previous work we have found strong indications that the misfit layered superconducting single crystal (LaSe)1.14(NbSe2) behaves like a 1 K analog of the 100 K high-Tc superconductor Bi2Sr2CaCu2Ox and that it may even exhibit the pseudogap behavior . Then, we have also shown that the in-plane upper critical magnetic field of the misfit strongly exceeds the Pauli limit . Recently, such strong upper critical fields have been detected in monolayer of NbSe2 with broken in-plane inversion symmetry and strong spin-orbit coupling . The effect has been explaiend by Ising pairing in superconducting atomic layers.
I will present scanning tunneling microscopy and spectroscopy measurements at very low temperatures and in high magnetic fields on (LaSe)1.14(NbSe2) and (LaSe)1.14(NbSe2)2 single crystals with the superconducting transition Tc around 1 K and 5 K, resp. Fourier transform of the surface topography maps shows besides the Bragg peaks due to hexagonal NbSe2 lattice also a long range modulation in the misfit direction and additional structures. Spectroscopy imaging STM conductance maps provide quasiparticle interference patterns indicating the Fermi surface similar to electron doped monolayer of NbSe2 with strong spin-orbit coupling and Ising pairing, The tunneling density of states indicates a non-conventional superconductivity.
In collaboration with Ondrej Šofranko, Pavol Szabó, Tomáš Samuely Jozef Ka？mar？ík, Shunsuke Sasaki, Laurent Cario, Raphaël. Leriche, Tristan Cren; I will briefly introduce the Centre of Ultra Low Temperature Physics Košice. References: 1. P. Szabó et al., Phys. Rev. Lett. 86, 5990 (2001); 2. P. Samuely et al., Physica C 369, 61 (2002); 3. X. Xi et al., Nature Phys. 12, 139 (2016).
Prof. Peter Samuely，PhD in Physics at P.J. Šafárik University of Košice, 1988; Full professor, P.J. Šafárik University of Košice, 2009. Researcher at Institute of Experimental Physics, Slovak Academy of Sciences, Košice since 1980; Vice President of the Slovak Academy of Sciences for Science, Research and Innovations, Bratislava, since 2017. Academician of the Slovak Learned society, 2008; Scientific Board of the Slovak Academy of Sciences, 2005 – 2013, 2017-. Scientific activities: Condensed matter physics at very low temperatures and high magnetic fields, highly correlated electron systems, novel superconductors. Point contact spectroscopy, scanning tunnelling spectroscopy, transport and thermodynamic measurements. Coordinator of numerous national and EU projects.