Ubiquitous stripe phase and enhanced electron pairing in interfacial high-Tc superconductor FeSe/BaTiO${}_3$

Abstract

Monolayer FeSe grown on SrTiO${}_3$ provides a new playground for high-Tc superconductivity. A recent study shows the importance of stripy instability for superconductivity enhancement in FeSe/SrTiO3. However, it is still under debate whether such a stripe phase is ubiquitously bound to the interfacial superconductivity. Here, we report on molecular beam epitaxy growth and low-temperature scanning tunneling microscopy study of FeSe films on BaTiO${}_3$(001). We find that the stripe phase is more prominent in FeSe/BaTiO${}_3$. Long-range stripes exist in bilayer and triple-layer FeSe films at 4 K and even persist up to 77 K in the case of bilayer FeSe, with enlarged superconducting gaps upon alkali-metal deposition. The results point out an intimate correlation between the interfacial superconductivity and the stripe phase.

Comments are welcome

References in corpus (10)

• Evidence for an electron nematic phase transition in underdoped iron pnictide superconductors
• A `checkerboard' electronic crystal state in lightly hole-doped Ca_{2-x}Na_{x}CuO_{2}Cl_{2}
• Electronic liquid crystal state in the high-temperature superconductor YBCO(6.45)
• Nematic and meta-nematic transitions in the iron pnictides
• Resonant X-ray Scattering Study of Charge Density Wave Correlations in YBa${}_2$Cu${}_3$O${}_{6+x}$
• Appearance of fluctuating stripes at the onset of the pseudogap in the high-Tc Superconductor Bi2Sr2CaCu2O8+x
• Revealing the Empty-State Electronic Structure of Single-Unit-Cell FeSe/SrTiO${}_3$
• Incommensurate smectic phase in close proximity to the high-Tc superconductor FeSe/SrTiO3
• Edge states at nematic domain walls in FeSe films
• Evolution of Charge and Pair Density Modulations in Overdoped Bi2Sr2CuO6+delta