Strong correlations in a two-dimensional kagome metal-organic framework

Place: "Isabel Rodríguez" room 215.

Abstract:
Two-dimensional (2D) and layered electronic materials characterized by a kagome lattice, whose valence band structure includes two Dirac bands and one flat band, can host a wide range of tunable topological and strongly correlated electronic phases. Here, direct experimental evidence of strong electron–electron Coulomb interactions in a 2D metal–organic framework (MOF) is reported. The MOF consists of 9,10-dicyanoanthracene (DCA) molecules arranged in a kagome structure via coordination with copper (Cu) atoms on a silver surface, Ag(111). Temperature-dependent scanning tunneling spectroscopy (STS) reveals the presence of local magnetic moments at DCA and Cu sites of the MOF which are Kondo screened by the Ag(111) conduction electrons. This is a signature created by strong electron-electron correlations within the MOF. We will also report further evidence for strongly correlated electrons detected in the same MOF on a thin insulating substrate. These are promising findings for controlling correlated electronic phases in 2D organic materials with the potential for nanoelectronics and spintronics technologies.