Related papers: Quasiparticle Interference Patterns in a Topologic…
A material whose electrons are correlated can affect electron dynamics across the interface with another material. Such a "proximity effect" can have several manifestations, from order parameter leakage to generated effective interactions.…
A magnetic field applied to type-II superconductors introduces quantized vortices that locally quench superconductivity, providing a unique opportunity to investigate electronic orders that may compete with superconductivity. This is…
We study theoretically the effects of random nonmagnetic impurities on the superconducting transition temperature $T_c$ in a two-band superconductor characterized by an equal-time s-wave interband pairing order parameter. The Fermi-Dirac…
The concept of topological insulator (TI) has introduced a new point of view to condensed-matter physics, relating a priori unrelated subfields such as quantum (spin, anomalous) Hall effects, spin-orbit coupled materials, some classes of…
We investigate the effects of magnetic and nonmagnetic impurities on the two-dimensional surface states of three-dimensional topological insulators (TIs). Modeling weak and strong TIs using a generic four-band Hamiltonian, which allows for…
The diversities in crystal structures and ways of doping result in extremely diversified phase diagrams for iron-based superconductors. With angle-resolved photoemission spectroscopy (ARPES), we have systematically studied the effects of…
We calculate superfluid density for a dirty d-wave superconductor. The effects of impurity scattering are treated within the self-consistent t-matrix approximation, in weak-coupling BCS theory. Working from a realistic tight-binding…
The local quasiparticle density of states around a unitary impurity with a Kondo-like magnetic moment induced at its nearest neighbors in a d-wave superconductor is studied within the slave-boson mean-field approach. The Hamiltonian is…
We study several aspects of the structure of vortices in conventional s-wave Type $II$ superconductors. It is well-known that there are low energy quasiparticles bound to the core of a vortex. We show that under certain conditions, these…
Exotic electronic states are realized in novel quantum materials. This field is revolutionized by the topological classification of materials. Such compounds necessarily host unique states on their boundaries. Scanning tunneling microscopy…
It has been observed that impurity doping and/or ion-beam-induced damage in high $T_{c}$ superconductors cause a metal-insulator transition and thereby suppress the critical temperature. Based on our recent theory of the weak localization…
Topological superconductivity is the quantum condensate of paired electrons with an odd parity of the pairing function. One of the candidates is the triplet pairing superconductor derived from topological insulator Bi2Se3 by chemical…
We investigate nonmagnetic impurity effects in two-band superconductors, focusing on the effects of interband scatterings. Within the Born approximation, it is known that interband scatterings mix order parameters in the two bands. In…
The quasiparticle lifetime and the related transport relaxation times are the fundamental quantities which must be known in order to obtain a description of the transport properties of the high T_c superconductors. Studies of these…
Although their crystal structures are complex, all high temperature superconductors contain some crystal planes consisting of only Cu and O atoms in a square lattice. Superconductivity is believed to originate from strongly interacting…
Topological phononic insulators are the counterpart of three-dimensional quantum spin Hall insulators in phononic systems and, as such, their topological surfaces are characterized by Dirac cone-shaped gapless edge states arising as a…
Based on a two-orbital model and taking into account the presence of the impurity, we studied theoretically the electronic structure in the vortex core of the iron-Pnictide superconducting materials. The vortex is pinned when the impurity…
We show that quasiparticle interference (QPI) due to omnipresent weak impurities and probed by Fourier transform scanning tunneling microscopy and spectroscopy acts as a direct experimental probe of bulk odd-frequency superconducting…
The inelastic scattering rates of quasiparticles in a two-dimensional d-wave superconductor, which arise from interactions with either acoustic phonons or other quasiparticles, are calculated within second order perturbation theory. We…
The impurity-induced quasiparticle interference(QPI) in the parent compounds of iron-pnictide superconductors is investigated based on a phenomenological two-orbital four-band model and T-matrix method. We find the QPI is sensitive to the…