Twisted bilayers: magic continuum, noncollinear magnetism and more
Van der Waals heterostructures provide a rich venue for exotic moir’e phenomena. In this talk, I will present a couple of unconventional examples beyond the celebrated twisted bilayer graphene. I will start by twisted bilayer of square lattice with staggered flux, which exhibits a continuum range of magic twisting angles where an exponential reduction of Dirac velocity and bandwidths occurs. Then I will discuss moir’e magnetism arising from twisted bilayers of antiferromagnets and also ferromagnets. Despite the fact that the parent materials all exhibit collinear orderings, the bilayer system shows controllable emergent noncollinear spin textures. Time permitting, I will also discuss a theory for the potentially continuous metal-insulator transition with fractionalized electric charges in transition metal dichalcogenide moir’e heterostructures.