Anisotropy of upper critical fields and interface superconductivity in FeSe/SrTiO3 grown by PLD

Abstract

In this study, we grow FeSe/SrTiO${}_3$ with thicknesses of 4-19 nm using pulsed laser deposition and investigate their magneto-transport properties. The thinnest film (4 nm) exhibit negative Hall effect, indicating electron transfer into FeSe from the SrTiO${}_3$ substrate. This is in agreement with reports on ultrathin FeSe/SrTiO${}_3$ grown by molecular beam epitaxy. The upper critical field is found to exhibit large anisotropy ($\gamma >$ 11.9), estimated from the data near the transition temperature ($T_{\mathrm{c}}$). In particular, the estimated coherence lengths in the perpendicular direction are 0.15-0.27 nm, which are smaller than the c-axis length of FeSe, and are found to be almost independent of the total thicknesses of the films. These results indicate that superconductivity is confined at the interface of FeSe/SrTiO${}_3$.

5pages, 3figures

References in corpus (5)

• Superconductivity in single-layer films of FeSe with a transition temperature above 100 K
• Incoherent Cooper pairing and pseudogap behavior in single-layer FeSe/SrTiO${}_3$
• Enhancement of superconducting transition temperature in electrochemically etched FeSe/LaAlO${}_3$ films
• Interface superconductivity in FeSe thin films on SrTiO${}_3$grown by the PLD technique
• Positive and negative chemical pressure effects investigated in electron-doped FeSe films with an electric-double-layer structure

Cited by in corpus (3)

• Study on fluctuations of interface-enhanced superconductivity in ultrathin FeSe/SrTiO3 by the Nernst effect
• Studies of superconductivity of Fe chalcogenides in films grown by PLD technique
• Fabrication of oxide/FeSe multilayer films using the PLD technique