Puzzling evidence for surface superconductivity in the layered dichalcogenide Cu${}_{10\%}$TiSe${}_2$

Abstract

We report on specific heat and magnetotransport measurements performed on superconducting Cu${}_{10\%}$TiSe${}_2$ single crystals. We show that superconductivity persists in transport measurements up to magnetic fields $H_R$ well above the upper critical field $H_{c2}$ deduced from the calorimetric measurements. Surprisingly this "surface" superconductivity is present for all magnetic field orientations, either parallel or perpendicular to the layers. For $H\Vert ab$, the temperature dependence of the $H_R/H_{c2}$ ratio can be well reproduced by solving the Ginzburg-Landau equations in presence of a surface layer with reduced superconducting properties. Unexpectedly this temperature dependence does not depend on the field orientation.

arXiv comment5 pages, 4 figures

References in corpus (13)

• Superconductivity in Cu_xTiSe_2
• Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB${}_2$
• Chiral charge-density-waves
• Theory of the striped superconductor
• Emergence of Fermi pockets in an excitonic CDW melted novel superconductor
• Superconducting Transition and Phase Diagram of Single Crystal MgB2
• The chiral phase transition in charge ordered 1T-TiSe2
• Specific-heat measurements of superconducting NbS2 single crystal in an external magnetic field: Study on the energy gap structure
• Chiral charge order in 1$T$-TiSe${}_2$: importance of lattice degrees of freedom
• Anisotropic properties of the layered superconductor Cu0.07TiSe2
• Exciton-phonon interactions and superconductivity bordering charge order in TiSe2
• Heat Capacity of Single Crystal CuxTiSe2 Superconductors
• Hidden Order as a Source of Interface Superconductivity

Cited by in corpus (5)

• Surface superconductivity as the primary cause of broadening of superconducting transition in Nb-films
• New Lithium- and Diamines-Intercalated Superconductors Li${}_x$(C${}_2$H${}_8$N${}_2$)${}_y$TiSe${}_2$ and Li${}_x$(C${}_6$H${}_{16}$N${}_2$)${}_y$TiSe${}_2$
• Onset of surface superconductivity beyond the Saint-James-de Gennes limit
• Magnetic and thermodynamic properties of Cu${}_x$TiSe${}_2$ single crystals
• Interplay between the charge density wave phase and a pseudogap under antiferromagnetic correlations