Benjamin Lowe, Monash
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. The presence of local magnetic moments at DCA and Cu sites of the MOF has previously been shown on Ag(111) – a signature of electron correlations within the MOF.
Here, via scanning tunnelling spectroscopy, we directly observe a ~200 meV bandgap associated with the formation of a Mott insulating phase within the MOF grown in an electronically decoupled environment on a monolayer of insulating hexagonal boron nitride (hBN). Furthermore, we can control metal-insulator transitions by changing electron filling of the kagome bands. These are promising findings for controlling correlated electronic phases in 2D organic materials with the potential for nanoelectronics and spintronics technologies.
About the presenter
Benjamin Lowe is a PhD student at Monash University where he works in Research theme 1 with A/Prof Agustin Schiffrin studying the self-assembly of metal-organic systems using a state-of-the-art scanning probe microscopy (SPM)facility that allows metal-organic systems to be engineered and probed with atomic-scale precision. He seeks to develop systems with electronic and opto-electronic properties that are of interest both fundamentally and for prospective electronics applications.