Related papers: Gap generation and flat band catalysis in dice mod…
We study by high-resolution transmission electron microscopy the structural response of bilayer graphene to electron irradiation with energies below the knock-on damage threshold of graphene. We observe that one type of divacancy, which we…
We describe the gated bilayer graphene system when it is subjected to intense terahertz frequency electromagnetic radiation. We examine the electron band structure and density of states via exact diagonalization methods within Floquet…
The effect of the four-spin cyclic exchange interaction at each plaquette in the $S=1/2$ two-leg spin ladder is investigated at T=0, especially focusing on the field-induced gap. The strong rung coupling approximation suggests that it…
Flat-band topologies and localizations in non-interacting systems are extensively studied in different quantum and classical-wave systems. Recently, the exploration on the novel physics of flat-band localizations and topologies in…
A symmetrically doped double layer electron system with total filling fraction $\nu=1/m$ decouples into two even denominator ($\nu=1/2 m$) composite fermion `metals' when the layer spacing is large. Out-of-phase fluctuations of the…
We investigate the spectral statistics of an interacting fermionic system derived by projecting the Hubbard interaction onto the two lowest-energy, degenerate flat bands of the dice lattice subjected to a $\pi$-flux. Surprisingly, the…
The critical theories for the topological phase transitions of integer quantum Hall states to a trivial insulating state with the same symmetry can be obtained by calculating the ground state entanglement spectrum under a symmetric…
We study the influence of strong spin-orbit interaction on the formation of flat bands in relaxed twisted bilayer WSe$_2$. Flat bands, well separated in energy, emerge at the band edges for twist angles ($\theta$) near 0$^{\circ}$ and…
We apply quantum continuum mechanics to the calculation of the excitation spectrum of a coupled electron-hole bilayer. The theory expresses excitation energies in terms of ground-state intra- and inter-layer pair correlation functions,…
The system under study is a twin-layered square lattice gas at half-filling, being driven to non-equilibrium steady states by a large, finite `electric' field. By making intra-layer couplings unequal we were able to extend the phase diagram…
Using the example of a two dimensional four-fermion lattice field theory we demonstrate that Feynman diagrams can generate a mass gap when massless fermions interact via a marginally relevant coupling. We introduce an infrared cutoff…
We locate gaps in the spectrum of a Hamiltonian on a periodic cuboidal (and generally hyperrectangular) lattice graph with $\delta$ couplings in the vertices. We formulate sufficient conditions under which the number of gaps is finite. As…
We investigate emergent topological gapless phases in the square-lattice Kitaev model with additional hopping terms. In the presence of nearest-neighbor hopping only, the model is known to exhibit gapless phases with two topological gapless…
Modulation of electronic states in two-dimensional (2D) materials can be achieved by using in-plane variations of the band gap or the average potential in lateral quantum structures. In the atomic configurations with hexagonal symmetry,…
We consider the pairing of electrons and holes due to their Coulomb attraction in two parallel, independently gated graphene layers, separated by a barrier. At weak coupling, there exist the BCS-like pair-condensed state. Despite the fact…
We report a dynamical formation of a (Mott) gap from holographic fermions. By coupling a fermion field with dipole action to the charged dilaton black branes with a Lifshitz like IR geometry and $AdS_{4}$ boundary, we find that when the…
We investigate the topological phases of the Haldane model on the Sierpi\'nski gasket. As a consequence of the fractal geometry, multiple fractal gaps arise. Additionally, a flat band appears, and due to a complex next-nearest neighbour…
We discuss in this study the possibility of finding a finite mass gap in the broken phase of the sine-Gordon model in $d=2$ using the functional flows. We demonstrate that the signal of the presence of massive excitations, a finite…
Generation of quasi-particle--hole pairs in gapped graphene monolayers in the combined field of two counterpropagating light waves is studied. The process represents an analogue of electron-positron pair production from the QED vacuum by…
The fate of a local two-hole doublon excitation in the one-dimensional Fermi-Hubbard model is systematically studied for strong Hubbard interaction U in the entire filling range using the density-matrix renormalization group (DMRG) and the…