Related papers: Interaction effect in two-dimensional Dirac fermio…
The dynamical conductivity of interacting multiband electronic systems derived in Ref.[1] is shown to be consistent with the general form of the Ward identity. Using the semiphenomenological form of this conductivity formula, we have…
The zero gap surface states of a 3D-topological insulator host Dirac fermions with spin locked to the momentum. The gap-less Dirac fermions exhibit electronic behaviour different from those predicted in conventional materials. While…
We investigate topological properties of a chiral honeycomb lattice model with next-nearest-neighbor hoppings characterized by the reflection symmetry breaking. Topological nontriviality is detected by analyzing effective Dirac Hamiltonian,…
Relativistic massless Weyl and Dirac fermions have isotropic and linear dispersion relations to maintain Poincar\'{e} symmetry, which is the most basic symmetry in high-energy physics. The situation in condensed matter physics is less…
We investigate the development of a gapped phase in the field theory of Dirac fermions in graphene with long-range Coulomb interaction. In the large-N approximation, we show that the chiral symmetry is only broken below a critical number of…
Three-dimensional topological insulators support gapless Dirac fermion surface states whose rich topological properties result from the interplay of symmetries and dimensionality. Their topological properties have been extensively studied…
The one dimension interacting Kitaev chain at half filling is studied. The symmetry of the Hamiltonian is examined by dual transformations and various physical quantities as functions of the fermion-fermion interaction $U$ are calculated…
We theoretically study topological phase transitions in four generalized versions of the Kane-Mele-Hubbard model with up to $2\times 18^2$ sites. All models are free of the fermion-sign problem allowing numerically exact quantum Monte Carlo…
Three-dimensional doped Dirac insulators foster simply connected (in both topological and trivial regimes) and annular (deep inside the topological regime) Fermi surfaces (FSs) in the normal state, and allow on-site repulsions among…
Surfaces of topological insulators host a new class of states with Dirac dispersion and helical spin texture. Potential quantum computing and spintronic applications using these states require manipulation of their electronic properties at…
We consider a clean two-dimensional interacting electron gas subject to a random perpendicular magnetic field, h({\bf r}). The field is nonquantizing, in the sense, that {\cal N}_h-a typical flux into the area \lambda_{\text{\tiny F}}^2 in…
We investigate some properties of a system of Dirac fermions in 2+1 dimensions, with a space dependent mass having domain wall like defects.These defects are defined by the loci of the points where the mass changes sign. In general, they…
Non-Hermitian systems give rise to distinct topological phenomena, yet their manifestations at temporal interfaces characterized by abrupt changes in system parameters remain largely unex plored. Upon an abrupt alteration of the Hamiltonian…
The Hubbard chain and spinless fermion chain are paradigms of strongly correlated systems, very well understood using Bethe ansatz, Density Matrix Renormalization Group (DMRG) and field theory/renormalization group (RG) methods. They have…
We explore a two-dimensional Hubbard model adapted to host altermagnetic states. Utilizing Hartree-Fock (HF) and dynamical mean field theory (DMFT), we uncover that the magnetic solutions of this model feature Dirac points in their…
Anderson localization is studied for two flavors of massless Dirac fermions in 2D space perturbed by static disorder that is invariant under a chiral symmetry (chS) and a time-reversal symmetry (TRS) operation which, when squared, is equal…
We present a theory describing the superconducting (SC) interaction of Dirac electrons in a quasi-two-dimensional system consisting of a stack of N planes. The occurrence of a SC phase is investigated both at T=0 and T\neq 0, in the case of…
We present a physical scenario in which both Fermi arcs and two-dimensional gapless Dirac states coexist as boundary modes at the same two-dimensional surface. This situation is realized in topological insulator-Weyl semimetal interfaces in…
I review results concerning the derivation of effective equations for the dynamics of interacting Fermi gases in a high-density regime of mean-field type. Three levels of effective theories, increasing in precision, can be distinguished:…
One of the most promising routes to non-fermi liquids and strange metals has been through SYK models \cite{Sachdev:2010um}, which necessarily involve large flavor degrees of freedom and interactions with imposed disorder. We introduce an…