Topological Doping of Correlated Insulators
نویسنده
چکیده
A material which is an insulator entirely because of interaction effects is called a correlated insulator. Examples are trans-polyacetylene and the cuprate high temperature superconductors. Whereas doping of a band insulator results in a shift of the chemical potential into the conduction or valence band, doping of a correlated insulator produces fundamental changes in the electronic density of states itself. We have found that a general feature of doping a correlated insulator is the generation of topological defects; solitons in one-dimension and anti-phase domain walls in higher dimensions. We review the well known features of this process in polyacetylene, and describe the experimental evidence that the analogous features are seen in the cuprate superconductors. We also distinguish the case in which the doping-induced features can be viewed as a Fermi surface instability, as in polyacetylene, and the more usual case in which they are a consequence of a Coulomb frustrated electronic tendency to phase separation. Paper presented at the Sixtieth Birthday Symposium for Alan J. Heeger, Jan-
منابع مشابه
Andreev reflection in two-dimensional topological insulators with either conserved or broken time-reversal symmetry
We investigate Andreev reflection in two-dimensional heterojunctions formed by a superconductor in contact with a topological insulator ribbon either possessing or breaking time-reversal symmetry. Both classes of topological insulators exhibit perfect Andreev reflection, which is robust against disorder. This is assigned to topologically protected edge states. In the time-reversal symmetric cas...
متن کاملInhomogeneity in doped Mott insulator
We introduce the concept that there are two generic classes of Mott insu-lators in nature. They are distinguished by their responses to weak doping. Doped charges form cluster (i.e. distribute inhomogeneously) in type I Mott insulators while distribute homogeneously in type II Mott insulators. We present our opinion on the role inhomogeneity plays in the cuprates.
متن کاملMagnetic doping and kondo effect in bi(2)se(3) nanoribbons.
A simple surface band structure and a large bulk band gap have allowed Bi2Se3 to become a reference material for the newly discovered three-dimensional topological insulators, which exhibit topologically protected conducting surface states that reside inside the bulk band gap. Studying topological insulators such as Bi2Se3 in nanostructures is advantageous because of the high surface-to-volume ...
متن کاملIndium Substitution Effect on the Topological Crystalline Insulator Family (Pb1-xSnx)1-yInyTe: Topological and Superconducting Properties
Topological crystalline insulators (TCIs) have been of great interest in the area of condensed matter physics. We investigated the effect of indium substitution on the crystal structure and transport properties in the TCI system (Pb1−xSnx)1−yInyTe. For samples with a tin concentration x ≤ 50%, the low-temperature resisitivities show a dramatic variation as a function of indium concentration: wi...
متن کاملMajorana modes at the ends of superconductor vortices in doped topological insulators.
Recent experiments have observed bulk superconductivity in doped topological insulators. Here we ask whether vortex Majorana zero modes, previously predicted to occur when s-wave superconductivity is induced on the surface of topological insulators, survive in these doped systems with metallic normal states. Assuming inversion symmetry, we find that they do but only below a critical doping. The...
متن کامل