Related papers: Tunable orbital susceptibility in $\alpha$-${\cal …
Ultraflat bands have already been detected in twisted bilayer graphene and twisted bilayer transition-metal dichalcogenides, which provide a platform to investigate strong correlations. In this paper, the electronic properties of twisted…
Topological semimetals are intensively studied in recent years. Besides the well known Weyl and Dirac semimetals, some materials possess nodes with linear crossing of multiple bands. Low energy excitations around these nodes are called…
We describe a versatile mechanism that provides tight-binding models with an enriched, topologically nontrivial bandstructure. The mechanism is algebraic in nature, and leads to tight-binding models that can be interpreted as a non-trivial…
The valence flat bands in transition metal dichalcogenide (TMD) heterobilayers are shown to exhibit strong intralayer spin-orbit coupling. This is reflected in a simple tight-binding model with spin-dependent complex hoppings based on the…
We report on terahertz time-domain spectroscopy on superconducting and metallic iron chalcogenides Rb$_{0.75}$Fe$_{1.6}$Se$_{2-z}$S$_z$. The superconducting transition is reduced from $T_c=$ 32 K ($z=0$) to 22 K ($z=1.0$), and finally…
The newly discovered iron-based superconductors have attracted lots of interests, and the corresponding theoretical studies suggest that the system should have six bands. In this paper, we study the multiband effects on the conductivity…
The emergence of strong relativistic spin-orbit effects in low-dimensional systems provides a rich opportunity for exploring unconventional states of matter. Here, we present a route to realise tunable relativistic band structures based on…
We perform a detailed analysis of electronic polarizability of graphene with different theoretical approaches. From Kubo's linear response formalism, we give a general expression of frequency and wave-vector dependent polarizability within…
Within the two-band model of superconductivity, we study the dependence of the critical temperature Tc and of the isotope exponent alpha in the proximity to an electronic topological transition (ETT). The ETT is associated with a 3D-2D…
A half-filled-band Hubbard model on an anisotropic triangular lattice (t in two bond directions and t' in the other) is studied using an optimization variational Monte Carlo method, to consider the Mott transition and superconductivity…
We investigate the crystal structure of YTiO3 at high pressures up to 30 GPa by synchrotron x-ray powder diffraction (T = 295 K). The variation of the Ti--O bond lengths with pressure evidences a distinct change in the distortion of the…
We study the spin-wave excitations in $\alpha$-RuCl$_3$ by the spin-wave theory. Starting from the five-orbital Hubbard model and the perturbation theory, we derive an effective isospin-$1/2$ model in the large Hubbard ($U$) limit. Based on…
We consider how electron-phonon interaction influences the insulator-metal transitions driven by doping in the strongly correlated system. Using the polaronic version of the generalized tight-binding method, we investigate a multiband…
We study theoretically ultracold collisions in quasi one-dimensional optical traps for bosonic and fermionic reactive molecules in the presence of a periodic potential along the trap axis. Elastic, reactive, and umklapp processes due to…
For a previously published study of the titanium hcp (alpha) to omega (omega) transformation, a tight-binding model was developed for titanium that accurately reproduces the structural energies and electron eigenvalues from all-electron…
In this paper we present a paradigmatic tight-binding model for single-layer as well as for multi-layered semiconducting MoS$_2$ and similar transition metal dichalcogenides. We show that the electronic properties of multilayer systems can…
Despite being of fundamental importance and potential interest for topological quantum computing, spin-triplet superconductors remain rare in solid state materials after decades of research. In this work, we present a general mechanism for…
Intrinsic and Rashba spin-orbit interactions in strained graphene is studied within the tight-binding (TB) approach. Dependence of Slater-Koster (SK) parameters of graphene on strain are extracted by fitting the \emph{ab initio} band…
In twisted h-BN/graphene heterostructures, the complex electronic properties of the fast-traveling electron gas in graphene are usually considered to be fully revealed. However, the randomly twisted heterostructures may also have unexpected…
We carry out both the tight-binding model and the $ab\ initio$ to study the layered silicene, the spin, valley, sublattice degrees of freedom are taken into consider and the effects of electric field, magnetic field, and even the light in…