Related papers: Quantum oscillations in a dipolar excitonic insula…
Quantum wells made of simple polyvalent metals represent a novel family of doped 2D Mott-Hubbard insulators. As scanning tunneling microscopy experiments show, these systems exhibit an anisotropic form of metal-insulator transition. Their…
We report a study of quantum oscillations in the high-field magneto-resistance of the nodal-line semimetal HfSiS. In the presence of a magnetic field up to 31 T parallel to the c-axis, we observe quantum oscillations originating both from…
Motivated by recent experiments on Kondo insulators, we theoretically study quantum oscillations from disorder-induced in-gap states in small-gap insulators. By solving a non-Hermitian Landau level problem that incorporates the imaginary…
We study the system consisted of two electrons in a quantum dot with a three-dimensional harmonic confinement potential under the effect of a magnetic field. Specifically, two different confinement conditions are considered, one isotropic…
Properties of a nonmagnetic impurity in Kondo insulators are investigated by considering a one-dimensional Kondo lattice model with depletion of a localized spin. The ground-state phase diagram determined by the Lanczos method shows that…
The electronic properties of a Kondo impurity are investigated in a magnetic field using linear response theory. The distribution of electrical charge and magnetic polarization are calculated in real space. The (small) magnetic field does…
We study the Coulomb drag between two spatially separated electron systems in a strong magnetic field, one of which exhibits the quantum Hall effect. At a fixed temperature, the drag mimics the behavior of $\sigma_{xx}$ in the quantum Hall…
Layered cobaltates embody novel realizations of correlated quantum matter on a spin-1/2 triangular lattice. We report a high-resolution systematic photoemission study of the insulating cobaltates (Na1/2CoO2 and K1/2CoO2). Observation of…
Recently a new phenomenological Hamiltonian has been proposed to describe the superconducting cuprates. This so-called Gossamer Hamiltonian is an apt model for a superconductor with strong on-site Coulomb repulsion betweenthe electrons. It…
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…
At low temperatures, indirect excitons formed at the in-plane electron-hole interface in a coupled quantum well structure undergo a spontaneous transition into a spatially modulated state. We report on the control of the instability…
We study theoretically a quantum dot in the quantum Hall regime that is strongly coupled to a single lead via a point contact. We find that even when the transmission through the point contact is perfect, important features of the Coulomb…
More than fifty years ago, excitonic insulators, formed by the pairing of electrons and holes due to Coulomb interactions, were first predicted. Since then, excitonic insulators have been observed in various classes of materials, including…
Kondo insulators are predicted to undergo an insulator-to-metal transition under applied magnetic field, yet the extremely high fields required to date have prohibited a comprehensive investigation of the nature of this transition. Here we…
The nature of a metal--insulator transition tuned by external gates in quantum Hall (QH) systems with point constrictions at integer bulk filling, as reported in recent experiments of Roddaro et al. [1], is addressed. We are particularly…
Exciton problem is solved in the two-dimensional Dirac model with allowance for strong electron-hole attraction. The exciton binding energy is assumed smaller than but comparable to the band gap. The exciton wavefunction is found in the…
Excitonic insulator is a coherent electronic phase that results from the formation of a macroscopic population of bound particle-hole pairs - excitons. With only a few candidate materials known, the collective excitonic behavior is…
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…
A novel magnetic interference effect is proposed for a neutral, but polarizable exciton in a quantum ring with a finite width. The magnetic interference effect originates from the nonzero dipole moment in the exciton. The ground state of…
Excitonic insulators conduct neither electrons nor holes but bound electron-hole pairs, excitons. Unfortunately, it is not possible to inject and detect the electron and hole currents independently within a single semiconducting layer.…