相关论文: Dirac-Harper Theory for One Dimensional Moir\'e Su…

Optical lattice systems offer the possibility of creating and tuning Dirac points which are present in the tight-binding lattice dispersions. For example, such a behavior can be achieved in the staggered flux lattice or honeycomb type of…

We investigate the spectrum and eigenstates of ultracold fermionic atoms in the bilayer honeycomb optical lattice. In the low energy approximation, the dispersion relation has parabolic form and the quasiparticles are chiral. In the…

The honeycomb supersolid state is predicted to form in a dipolar Bose-Einstein condensate with a planar confining potential. Our results for its excitation spectrum reveal the gapless bands and the emergence of Dirac points at the Brillouin…

We have theoretically investigated two-band models of graded-gap superlattices within the envelope-function approximation. Assuming that the gap varies linearly with spatial coordinate, we are able to find exact solutions of the…

Graphene-based superlattice (SL) formed by a periodic gap modulation is studied theoretically using a Dirac-type Hamiltonian. Analyzing the dispersion relation we have found that new Dirac points arise in the electronic spectrum under…

Dirac spin liquids represent a class of highly-entangled quantum phases in two dimensional Mott insulators, featuring exotic properties such as critical correlation functions and absence of well-defined low energy quasi-particles. Existing…

In this paper I construct the naive lattice Dirac Hamiltonian describing the propagation of fermions in a generic 2D optical metric for different lattice and flux-lattice geometries. First, I apply a top-down constructive approach that we…

Motivated by the recent realization of the three-dimensional hyperhoneycomb and stripyhoneycomb lattices in lithium iridate (Li$_2$IrO$_3$), we study the possible spin-singlet superconducting states on the whole series of harmonic honeycomb…

We investigate the spectral properties of a quasi-one-dimensional lattice in two possible dimerisation configurations. Both configurations are characterized by the same lattice topology and the identical spectra containing a flat band at…

We study interlayer excitons in MoSe2/WSe2 heterobilayers, by combining lateral force microscopy and micro-photoluminescence spectroscopy. This allows us to correlate the spatial profile of the moir\'e superlattice with the distribution of…

Patterning graphene with a spatially-periodic potential provides a powerful means to modify its electronic properties. Dramatic effects have been demonstrated in twisted bilayers where coupling to the resulting moir\'e-superlattice yields…

The Harper equation arising out of a tight-binding model of electrons on a honeycomb lattice subject to a uniform magnetic field perpendicular to the plane is studied. Contrasting and complementary approaches involving von Neumann entropy,…

We study the dynamics of discrete breathers -- spatially localized and time-periodic solutions -- inside the bandgap of a nonlinear honeycomb lattice where the dispersion landscape approaches a so-called semi-Dirac point in which the bands…

Experiments conducted on two-dimensional twisted materials have revealed a plethora of moir\'e patterns with different forms and shapes. The formation of these patterns is usually attributed to the presence of small strains in the samples,…

We formulate a low energy effective Hamiltonian to study superlattices in bilayer graphene (BLG) using a minimal model which supports quadratic band touching points. We show that a one dimensional (1D) periodic modulation of the chemical…

Strain-induced lattice mismatch leads to moir\'{e} patterns in homobilayer transition metal dichalcogenides (TMDs). We investigate the structural and electronic properties of such strained moir\'{e} patterns in TMD homobilayers. The…

We consider the $Sp(4)$ gauge theory coupled to $N_f=2$ fundamental and $n_f=3$ antisymmetric flavours of Dirac fermions in four dimensions. This theory serves as the microscopic origin for composite Higgs models with $SU(4)/Sp(4)$ coset,…

We discuss the emergence and manipulation of generalised Dirac cones in the subradiant collective modes of quantum metasurfaces. We consider a collection of single quantum emitters arranged in a honeycomb lattice with subwavelength…

Moir\'e superlattices are generally assumed to act only at the interface where lattice mismatch or twist occurs. Here, we study charge transport in large-angle helical twisted trilayer graphene, where interlayer tunneling is strongly…

We propose to realize Dirac states in an inclined two-dimensional Su-Schrieffer-Heeger model on a square lattice. We show that a pair of Dirac points protected by space-time inversion symmetry appear in the semimetal phase. The locations of…