Image-potential states on a 2D Gr-ferromagnet hybrid: enhancing spin and stacking sensing

Abstract

Spin-resolved scanning tunneling microscopy and spectroscopy studies of image-potential states on Gr/Fe/Ir(111) show their sensitivity to the spatial variation of the Gr-Fe distance, and of the interfacial charge and spin transfer within the moiré unit cell. A stacking contrast between fcc and hcp sites, indistinguishable in the direct tunneling mode, is provided by the image-potential states in both resonant tunneling topography and spectroscopy images. The spin-polarized measurements reveal a site- and energy-dependent spin-polarization of the image-potential states that is mapped across the moiré unit cell with a spin contrast between hcp and fcc sites unobservable in direct tunneling mode. On the on-top sites, the lowest image-potential states are found to exhibit a high spin-polarization, in contrast to the electronic states around the Fermi energy evanescent into vacuum, and attributed to their interfacial character at the respective Gr-Fe distance. Since the physisorbed graphene is only weakly spin-polarized on these sites, image-potential states reflect the spin density at buried interfaces covered by non-magnetic passivation layers. The simultaneous imaging of structural, electronic and magnetic properties, both at the surface and the buried interface will prove invaluable in research of 2D hybrids and heterostructures.

43 pages, 14 figures

References in corpus (15)

• Is graphene on Ru(0001) a nanomesh?
• Induced magnetism of carbon atoms at the graphene/Ni(111) interface
• Graphene on metallic surfaces: problems and perspectives
• Potential Energy Landscape for hot electrons in periodically nanostructured graphene
• Image potential states as quantum probe of graphene interfaces
• Multi-scale magnetic study on Ni(111) and graphene on Ni(111)
• Lifetimes of Stark-shifted image states
• Nanoscale probing of image-potential states and electron transfer doping in borophene polymorphs
• Graphene based quantum dots
• Multichannel scanning probe microscopy and spectroscopy of graphene moire structures
• Formation of image-potential states at the graphene/metal interface
• Resolubility of Image-Potential Resonances
• Real-space imaging of atomic-scale spin textures at nanometer distances
• Probing weakly hybridized magnetic molecules by spin-polarized tunneling
• Probing the graphene/substrate interaction by electron tunneling decay