Observation of novel gapped phases in potassium doped single layer p-terphenyl on Au (111)

Abstract

Recently, superconductivity in potassium (K) doped p-terphenyl (C18H14) has been suggested by the possible observation of the Meissner effect and subsequent photoemission spectroscopy measurements, but the detailed lattice structure and more-direct evidence are still lacking. Here we report a low temperature scanning tunneling microscopy/spectroscopy (STM/STS) study on K-doped single layer p-terphenyl films grown on Au (111). We observe several ordered phases with different morphologies and electronic behaviors, in two of which a sharp and symmetric low-energy gap of about 11 meV opens below 50 K. In particular, the gap shows no obvious response to a magnetic field up to 11 Tesla, which would caution against superconductivity as an interpretation in previous reports of K-doped p-terphenyl materials. Such gapped phases are rarely (if ever) observed in single layer hydrocarbon molecular crystals. Our work also paves the way for fabricating doped two-dimensional (2D) hydrocarbon materials, which will provide a platform to search for novel emergent phenomena.

arXiv comment16 pages, 10 figures

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Cited by in corpus (6)

• Spectroscopic Evidence of Low Energy Gaps Persisting Towards 120 Kelvin in Surface-Doped p-Terphenyl Crystals
• Anisotropic thermal expansion of p-Terphenyl: a self-assembled supramolecular array of poly-p-phenyl nanoribbons
• Potassium-Doped Para-Terphenyl: Structure, Electrical Transport Properties and Possible Signatures of a Superconducting Transition
• Infrared ellipsometry study of the charge dynamics in K3p-terphenyl
• Superconductivity from Meissner Effect and Zero Resistivity in a Phenyl Molecule
• Novel solid state vacuum quartz encapsulated growth of p-Terphenyl: the parent High Tc Oraganic Superconductor (HTOS)