Transport experiments in twisted bilayer graphene haverevealed multiple superconducting domes separated by cor-related insulating states 1–5 . These properties are generallyassociated with strongly... Show moreTransport experiments in twisted bilayer graphene haverevealed multiple superconducting domes separated by cor-related insulating states 1–5 . These properties are generallyassociated with strongly correlated states in a flat mini-bandof the hexagonal moiré superlattice as was predicted by bandstructure calculations 6–8 . Evidence for the existence of a flatband comes from local tunnelling spectroscopy 9–13 and elec-tronic compressibility measurements 14 , which report two ormore sharp peaks in the density of states that may be asso-ciated with closely spaced Van Hove singularities. However,direct momentum-resolved measurements have proved to bechallenging 15 . Here, we combine different imaging techniquesand angle-resolved photoemission with simultaneous real- andmomentum-space resolution (nano-ARPES) to directly mapthe band dispersion in twisted bilayer graphene devices nearcharge neutrality. Our experiments reveal large areas with ahomogeneous twist angle that support a flat band with a spec-tral weight that is highly localized in momentum space. The flatband is separated from the dispersive Dirac bands, which showmultiple moiré hybridization gaps. These data establish thesalient features of the twisted bilayer graphene band structure. Show less
This thesis describes a series of measurements and a theoretical analysis to get more insight into the fundamental working of superconducting systems when these are brought into close proximity... Show moreThis thesis describes a series of measurements and a theoretical analysis to get more insight into the fundamental working of superconducting systems when these are brought into close proximity with ferromagnetic systems, or when they are driven into a non-equilibrium state. The main focus is on the electronic transport properties of such coupled systems, from which the working of the individual part are well known. Show less
