Reproducibility in the fabrication and physics of moiré materials
Overlaying two atomic layers with a slight lattice mismatch or at a small rotation angle
creates a moiré superlattice, which has properties that are markedly modified from (and at …
creates a moiré superlattice, which has properties that are markedly modified from (and at …
Superconductivity, superfluidity and quantum geometry in twisted multilayer systems
Superconductivity has been observed in moiré systems such as twisted bilayer graphene,
which host flat, dispersionless electronic bands. In parallel, theory work has discovered that …
which host flat, dispersionless electronic bands. In parallel, theory work has discovered that …
Magic-angle twisted bilayer graphene as a topological heavy fermion problem
ZD Song, BA Bernevig - Physical review letters, 2022 - APS
Magic-angle (θ= 1.0 5°) twisted bilayer graphene (MATBG) has shown two seemingly
contradictory characters: the localization and quantum-dot-like behavior in STM …
contradictory characters: the localization and quantum-dot-like behavior in STM …
Evidence for Dirac flat band superconductivity enabled by quantum geometry
In a flat band superconductor, the charge carriers' group velocity v F is extremely slow.
Superconductivity therein is particularly intriguing, being related to the long-standing …
Superconductivity therein is particularly intriguing, being related to the long-standing …
Graphene bilayers with a twist
EY Andrei, AH MacDonald - Nature materials, 2020 - nature.com
Near a magic twist angle, bilayer graphene transforms from a weakly correlated Fermi liquid
to a strongly correlated two-dimensional electron system with properties that are …
to a strongly correlated two-dimensional electron system with properties that are …
Twisted bilayer graphene. IV. Exact insulator ground states and phase diagram
We derive the exact insulator ground states of the projected Hamiltonian of magic-angle
twisted bilayer graphene (TBG) flat bands with Coulomb interactions in various limits, and …
twisted bilayer graphene (TBG) flat bands with Coulomb interactions in various limits, and …
Revisiting flat band superconductivity: Dependence on minimal quantum metric and band touchings
KE Huhtinen, J Herzog-Arbeitman, A Chew… - Physical Review B, 2022 - APS
A central result in superconductivity is that flat bands, though dispersionless, can still host a
nonzero superfluid weight due to quantum geometry. We show that the derivation of the …
nonzero superfluid weight due to quantum geometry. We show that the derivation of the …
Twisted bilayer graphene. III. Interacting Hamiltonian and exact symmetries
We derive the explicit Hamiltonian of twisted bilayer graphene (TBG) with Coulomb
interaction projected into the flat bands and study the symmetries of the Hamiltonian. First …
interaction projected into the flat bands and study the symmetries of the Hamiltonian. First …
Twisted bilayer graphene. V. Exact analytic many-body excitations in Coulomb Hamiltonians: Charge gap, Goldstone modes, and absence of Cooper pairing
We find exact analytic expressions for the energies and wave functions of the charged and
neutral excitations above the exact ground states (at rational filling per unit cell) of projected …
neutral excitations above the exact ground states (at rational filling per unit cell) of projected …
Kondo lattice model of magic-angle twisted-bilayer graphene: Hund's rule, local-moment fluctuations, and low-energy effective theory
We apply a generalized Schrieffer-Wolff transformation to the extended Anderson-like
topological heavy fermion (THF) model for the magic-angle (θ= 1.0 5°) twisted bilayer …
topological heavy fermion (THF) model for the magic-angle (θ= 1.0 5°) twisted bilayer …