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Enumeration of Moiré patterns of a hexagonal twisted bilayer: Applications to intercalated transition metals
A real-space method using generating integers is used to determine possible commensurate lattice Moiré patterns for a bilayer of two equal hexagonal lattices, which can in principle be extended to lattice mismatched bilayers. These Moiré patterns can be classified by a pair of relatively prime integers (n,m), wherein a rotation θ(n,m) of the top hexagonal lattice maps its lattice vector (n,m) to (m,n) of the bottom lattice. Within this formulation, the area of the commensurate supercell is proportional to (n2+m2+nm) and the number of coincident lattice sites per supercell is given by (n−m)2. Taking bilayer boron nitride (BN) as an example, we present how to systematically generate Moiré patterns and explore the differences in local chemistry in the interstitial region by impurity intercalation. Systematic calculations of the properties of intercalated 3d transition metals were performed in an h-BN (4,3) bilayer, corresponding to a rotation of 9.43 degrees. These calculations reveal that local symmetry in the intercalated region significantly affect the energetics and magnetization of the intercalated species. These results highlight that Moiré pattern physics is not limited to optoelectronic/electronic phenomena, such as interfacial exciton formation or magic angle superconductivity, but it also produces chemical and magnetic atomic site selectivity, which may play important roles in adsorption, catalysis, or quantum information.
Terahertz circular dichroism in commensurate twisted bilayer graphene
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Fractional Chern insulators versus nonmagnetic states in twisted bilayer MoTe 2
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Moiré fractional Chern insulators. I. First-principles calculations and continuum models of twisted bilayer MoTe 2
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Contrasting twisted bilayer graphene and transition metal dichalcogenides for fractional Chern insulators: An emergent gauge picture
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Elastic plate basis for the deformation and electron diffraction of twisted bilayer graphene on a substrate
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Fractional Chern Insulators in Twisted Bilayer MoTe 2 : A Composite Fermion Perspective
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First-principles electron-phonon interactions and electronic transport in large-angle twisted bilayer graphene
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Fractional Chern insulator states in twisted bilayer graphene: An analytical approach
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Correlation-Induced Insulating Topological Phases at Charge Neutrality in Twisted Bilayer Graphene
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Twisted bilayer graphene: topological pumping and switching of topology by current [Slides]
The presentation was prepared for a BLABS seminar and includes various graphical images. The summary given highlighted: Topological pumping can be triggered by interlayer sliding in TBG due to the nontrivial topology associated with the synthetic dimension; Time-reversal symmetry of TBG can be spontaneously broken by Coulomb interaction, that results in the valley-polarized QAH state at 3/4 filling; A large enough current can pump electrons from the valence band to conductance band, that redistributes the electron occupation; and, the redistribution of electron occupation combined with the Coulomb interaction can switch the valley polarization and topology.
Magnetic anisotropy in twisted bilayer graphene and ABC-trilayer graphene aligned with hexagonal boron nitride.
Abstract not provided.
An accurate tight binding model for twisted bilayer graphene describes topological flat bands without geometric relaxation.
Abstract not provided.