相关论文: Gapped Dirac semimetal with mixed linear and parab…
In this paper, we give a systematic theoretical study on the Landau levels (LLs) and magneto-optical conductivity Re$(\sigma_{\alpha\alpha})$ in a gapped Dirac semimetal model with mixed linear and parabolic dispersions under a magnetic…
We consider the optical and transport properties in a model two-dimensional Hamiltonian which describes the merging of two Dirac points. At low energy, in the presence of an energy gap parameter $\Delta$, there are two distinct Dirac points…
Two-dimensional (2D) semi-Dirac materials feature a unique anisotropic band structure characterized by quadratic dispersion along one spatial direction and linear dispersion along the other, effectively hybridizing ordinary and Dirac…
Three dimensional (3D) topological Dirac materials are under intensive study recently. The layered compound ZrTe$_5$ has been suggested to be one of them by transport and ARPES experiments. Here, we perform infrared reflectivity measurement…
The experimental discovery of the topological Dirac semimetal establishes a platform to search for various exotic quantum phases in real materials. ZrSiS-type materials have recently emerged as topological nodal-line semimetals where gapped…
Weyl and Dirac (semi)metals in three dimensions have robust gapless electronic band structures. Their massless single-body energy spectra are protected by symmetries such as lattice translation, (screw) rotation and time reversal. In this…
Correlated Dirac semimetal phases emerge in lightly doped (Tb- or La-doped) Mott insulator Sr$_2$IrO$_4$, where a d-wave symmetry-breaking order underlying a pseudogap plays a crucial role in determining the nature of Dirac degeneracy,…
We study the interaction effect in a three dimensional Dirac semimetal and find that two competing orders, charge-density-wave orders and nematic orders, can be induced to gap the Dirac points. Applying a magnetic field can further induce…
We report a room-temperature optical reflectivity study performed on [112]-oriented Cd$_3$As$_2$ single crystals over a broad energy range under external pressure up to 10 GPa. The abrupt drop of the band dispersion parameter…
We theoretically study intrinsic superconductivity in doped Dirac semimetals. Dirac semimetals host bulk Dirac points, which are formed by doubly degenerate bands, so the Hamiltonian is described by a $4 \times 4$ matrix and six types of…
The interband optical response of a three-dimensional Dirac cone is linear in photon energy ($\Omega$). Here, we study the evolution of the interband response within a model Hamiltonian which contains Dirac, Weyl and gapped semimetal…
In a Dirac semimetal, the conduction and valence bands contact only at discrete (Dirac) points in the Brillouin zone (BZ) and disperse linearly in all directions around these critical points. Including spin, the low energy effective theory…
We measured the optical reflectivity of [001]-oriented $n$-doped Cd$_{3}$As$_{2}$ in a broad frequency range (50 - 22000 cm$^{-1}$) for temperatures from 10 to 300 K. The optical conductivity, $\sigma(\omega) = \sigma_{1}(\omega) + {\rm…
We report a theoretical \textit{ab-initio} study of $\beta$-As$_2$Te$_3$ ($R\bar{3}m$ symmetry) at hydrostatic pressures up to 12 GPa. We have systematically characterized the vibrational and electronic changes of the system induced by the…
Since the discovery of graphene, layered materials have attracted extensive interests owing to their unique electronic and optical characteristics. Among them, Dirac semimetal, one of the most appealing categories, has been a long-sought…
Novel phases of matter with unique properties that emerge from quantum and topological protection present an important thrust of modern research. Of particular interest is to engineer these phases on demand using ultrafast external stimuli,…
Holographic quantum matter exploits the AdS/CFT correspondence to study systems in condensed matter physics. An example of these systems are strongly correlated semimetals, which feature a rich phase diagram structure. In this work, we…
Vortex lines in superconducting Dirac semimetals realize crystal-symmetry-protected gapless vortex-line phases in which gapless excitations propagate inside a vortex line, in the presence of appropriate crystal symmetry, spin-orbit…
Two-dimensional Dirac semimetals have attracted much attention because of their linear energy dispersion and non-trivial Berry phase. Graphene-like 2D Dirac materials are gapless only within certain approximations, e.g., if spin-orbit…
We study the low-energy electronic structure of three-dimensional Dirac semimetal, Cd$_3$(As$_{1-x}$P$_x$)$_2$ [$x$ = 0 and 0.34(3)], by employing the angle-resolved photoemission spectroscopy (ARPES). We observe that the bulk Dirac states…