Origami-controlled strain engineering of tunable flat bands and correlated states in folded graphene

Flat electronic bands with tunable structures offer opportunities for the exploitation and manipulation of exotic interacting quantum states. Here, we present a controllable route to construct easily flat in folded graphene by nano origami-controlled strain engineering, discover correlated states this system. Via tearing folding monolayer at arbitrary step edges scanning tunneling microscope manipulation, create strain-induced pseudomagnetic fields as well resulting curved graphene. We show that intensity field can be readily tuned changing width edge due edge-width-dependent lattice deformation, leading adjustability geometry Furthermore, creating expected dispersionless using technique, correlation-induced splits are successfully observed density when these partially filled. Our experiment provides feasible effective pathway engineer system band structures, it establishes platform used realize devisable interaction-induced phases.