Related papers: Spin density wave and electron nematicity in magic…
Motivated by the recently discovered bilayer nickelate superconductor, the pressurized $\rm{La}_{3}Ni_{2}O_{7}$, we present a renormalized mean-field theory of a bilayer single-band $t$-$J$ model, highlighting the interplay between…
Twist bilayer graphenes with magical angle have nearly flat band, which become strongly correlated electron systems. Herein, we propose another system based on strained bilayer graphene that have flat band at the intrinsic Fermi level. The…
The electronic and optical properties of nonuniform bilayer graphene nanoribbons are worth investigating as they exhibit rich magnetic quantization. Based on our numerical results, their electronic and optical properties strongly depend on…
One of the outstanding questions in the study of twisted bilayer graphene -- from both experimental and theoretical points of view -- is the nature of its superconducting phase. In this work we perform a comprehensive synthesis of existing…
When two graphene layers are rotated from AA or AB configuration by a small angle, the band structure changes dramatically. Numerical calculations have shown that, at certain discrete angles called magic angles, the low energy bands become…
We study the single- and many-particle properties of a two-leg ladder model threaded by a flux with the legs coupled by a spatially varying term. Although a priori unrelated to twisted bilayer graphene (TBG), the model is found to have…
Rhombohedral stacked multilayer graphene displays the occurrence of a magnetic surface state at low temperatures. Recent angular resolved photoemission experiments demonstrate the robustness of the magnetic state in long sequences of ABC…
The emergence of flat bands and correlated behaviors in 'magic angle' twisted bilayer graphene (tBLG) has sparked tremendous interest, though many aspects of the system are under intense debate. Here we report observation of both…
Spin-polarized band calculations for supercells of SrB$_{6}$, where a La-, In- or Al- impurity or a vacancy is replacing one Sr, are performed within the local spin density approximation. Moderately large cells with 8 formula units (56…
Entanglement of spin and orbital degrees of freedom, via relativistic spin-orbit coupling, in 4$d$ transition metal oxides can give rise to a variety of novel quantum phases. A previous study of mixed 3$d$-4$d$ quasi-1D spin-chain oxide…
We investigate the correlated electrons in the magic-angle twisted bilayer graphene by using the slave-rotor mean-field theory. Owing to the extended figure of Wannier orbitals, we study the two-orbital cluster Hubbard model with…
Electronic structure and magnetic interactions of a Tb adatom on graphene are investigated from first principles using combination of density functional theory and multiconfigurational quantum chemistry techniques including spin-orbit…
We propose a class of graphene nanoribbons showing strong intrinsic ferromagnetic behavior due to their asymmetry. Such ribbons are based on a zig-zag edged backbone surmounted by a periodic, triangular notched region of variable size. The…
Superconductivity in strongly correlated electron systems frequently exhibits broken rotational symmetry, raising fundamental questions about the underlying order parameter symmetry. In this work, we demonstrate that electronic…
We present a detailed theoretical study of bilayer-graphene's electronic properties in the presence of electric and magnetic fields. Using group-theoretical methods, we derive an invariant expansion of the Hamiltonian for electron states…
We introduce a minimum tight-binding model with only three parameters extracted from graphene and untwisted bilayer graphene. This model reproduces quantitatively the electronic structure of not only these two systems and bulk graphite near…
The spin-polarized electronic structure and half-metallicity of zigzag graphene nanoribbons (ZGNRs) with asymmetric edge terminations are investigated by using first principles calculations. It is found that compared with symmetric…
We determine the stability, the geometry, the electronic and magnetic structure of hydrogen-terminated graphene-nanoribbons edges as a function of the hydrogen content of the environment by means of density functional theory.…
We study the magnetic properties of nanometer-sized graphene structures with triangular and hexagonal shapes terminated by zig-zag edges. We discuss how the shape of the island, the imbalance in the number of atoms belonging to the two…
A number of moir\'e graphene systems have nearly flat topological bands where electron motion is strongly correlated. Though microscopically these systems are only quasiperiodic, they can typically be treated as translation invariant to an…