Abstract

This study theoretically investigates the contact conductance in twisted bilayer graphene (TBG), providing a theoretical explanation for recent experimental observations from scanning tunneling microscopy (STM) and conductive atomic force microscopy (c-AFM). These experiments revealed a surprising non-monotonic current pattern as a function of the TBG rotation angle θ, with a peak at θ ≈5◦. The work develops a computational framework combining lattice relaxation and electronic structure calculations to show that the conductance maximum is not caused by structural relaxation or AA-stacking changes, but by the evolution of the electronic band structure, especially the shifting of van Hove singularities to the Fermi level as the twist angle decreases.

Abstract

This study theoretically investigates the contact conductance in twisted bilayer graphene (TBG), providing a theoretical explanation for recent experimental observations from scanning tunneling microscopy (STM) and conductive atomic force microscopy (c-AFM). These experiments revealed a surprising non-monotonic current pattern as a function of the TBG rotation angle θ, with a peak at θ ≈5◦. The work develops a computational framework combining lattice relaxation and electronic structure calculations to show that the conductance maximum is not caused by structural relaxation or AA-stacking changes, but by the evolution of the electronic band structure, especially the shifting of van Hove singularities to the Fermi level as the twist angle decreases.

Abstract

This study theoretically investigates the contact conductance in twisted bilayer graphene (TBG), providing a theoretical explanation for recent experimental observations from scanning tunneling microscopy (STM) and conductive atomic force microscopy (c-AFM). These experiments revealed a surprising non-monotonic current pattern as a function of the TBG rotation angle θ, with a peak at θ ≈5◦. The work develops a computational framework combining lattice relaxation and electronic structure calculations to show that the conductance maximum is not caused by structural relaxation or AA-stacking changes, but by the evolution of the electronic band structure, especially the shifting of van Hove singularities to the Fermi level as the twist angle decreases.

Abstract

This study theoretically investigates the contact conductance in twisted bilayer graphene (TBG), providing a theoretical explanation for recent experimental observations from scanning tunneling microscopy (STM) and conductive atomic force microscopy (c-AFM). These experiments revealed a surprising non-monotonic current pattern as a function of the TBG rotation angle θ, with a peak at θ ≈5◦. The work develops a computational framework combining lattice relaxation and electronic structure calculations to show that the conductance maximum is not caused by structural relaxation or AA-stacking changes, but by the evolution of the electronic band structure, especially the shifting of van Hove singularities to the Fermi level as the twist angle decreases.