Related papers: Tunable excitonic insulator in quantum limit graph…
Excitonic insulators are long-sought-after quantum materials predicted to spontaneously open a gap by the Bose condensation of bound electron-hole pairs, namely, excitons, in their ground state. Since the theoretical conjecture, extensive…
The interplay between topology and correlations can generate a variety of quantum phases, many of which remain to be explored. Recent advances have identified monolayer WTe2 as a promising material for doing so in a highly tunable fashion.…
Superconductivity with transition temperature $T_c=1.7$ K has been reported in bilayer graphene [1,2]. The main factors, which may shed light on the mechanism of the formation of this superconductivity, are the following. Superconductivity…
The recently observed superconductivity in twisted bilayer graphene emerges from insulating states believed to arise from electronic correlations. While there have been many proposals to explain the insulating behaviour, the…
We introduce a generalized Gross-Neveu (GN) model to describe the excitonic instabilities in two different systems: a small overlap semi-metal (SM) and a small gap semi-conductor (SMC), both in two (2d) and three-dimensions (3d). We…
Motivated by experiments in which the quantum anomalous Hall (QAH) charge gap greatly exceeds the Curie temperature, we apply determinantal quantum Monte Carlo to two complementary lattice models with different geometries: the checkerboard…
Realizing an excitonic insulator phase from narrow-gap semiconductors remains challenging, as unambiguous experimental signatures are difficult to establish. Ta$_2$NiSe$_5$ has been widely regarded as a leading candidate, yet the nature of…
A state of an excitonic insulator with the electric current is studied. Initially, in the metallic phase, the electrons and holes are assumed to be moving in the opposite directions, so as the electric current exists. This state is…
An excitonic insulator$^{1,2}$ (EI) is a correlated many-body state of electron-hole pairs, potentially leading to high-temperature condensate and superfluidity$^{3-7}$. Despite ever-growing experiments suggesting possible EI states in…
We show that the coupling to vibrational degrees of freedom can drive a semimetal excitonic-insulator quantum phase transition in an one-dimensional two-band f-c electron system at zero temperature. The insulating state typifies an…
The opening of an energy gap in the electronic structure generally indicates the presence of interactions. In materials with low carrier density and short screening length, long-range Coulomb interaction favors the spontaneous formation of…
In graphite, a moderate magnetic field confines electrons and holes into their lowest Landau levels. In the extreme quantum limit, two insulating states with a dome-like field dependence of the their critical temperatures are induced by the…
Although predicted theoretically excitonic phase transitions have never been observed. Recently it has been claimed that they can occur in some strongly correlated materials. We study the possibility of an excitonic transition in a two-band…
In this paper, we consider the spectral properties of the bilayer graphene with the local excitonic pairing interaction between the electrons and holes. We consider the generalized Hubbard model, which includes both intralayer and…
Despite a long history, certain aspects of excitons - the bound inter-band states which form when a valence band hole and a conduction band electron pair - have remained relatively unexplored. This holds particularly true for the…
The interaction driven transition between quantum spin-Hall and Mott insulators in the Bernevig, Hughes and Zhang model is studied by dynamical cluster approximation, and found to be accompanied by the emergence of Green's function zeros…
Monolayer transition metal dichalcogenides in the T' phase promise to realize the quantum spin Hall (QSH) effect at room temperature, because they exhibit a prominent spin-orbit gap between inverted bands in the bulk. Here we show that the…
Excitonic insulators represent a unique quantum phase of matter, providing a rich ground for studying exotic quantum bosonic states. Strongly coupled electron-hole bilayers, which host stable dipolar exciton fluids with an exciton density…
We present a theoretical study of electronic transport in a hybrid junction consisting of an excitonic insulator sandwiched between a normal and a superconducting electrode. The normal region is described as a two-band semimetal and the…
Tuning many-body electronic phases by an external handle is of both fundamental and practical importance in condensed matter science. The tunability mirrors the underlying interactions, and gigantic electric, optical and magnetic responses…