Probing crossover from analogous weak antilocalization to localization by an Aharonov-Bohm interferometer on topological insulator surface

We propose a scanning tunneling microscopy Aharonov-Bohm (AB) interferometer on the surface of a topological insulator (TI) to probe the crossover from analogous weak antilocalization (WAL) to weak localization (WL) phenomenon via the AB oscillations in spin-resolved local density of states (LDOS). Based on our analytical and numerical results, we show that with increasing the energy gap of TI surface states, the $\Phi_{0}/2$=$hc/2e$ periodic AB oscillations in spin-resolved LDOS gradually transit into the $\Phi_{0}$ periodic oscillations.Comment: 4.2 APL pages, 2 figure

Aharonov-Bohm oscillations in the local density of topological surface states

We study Aharonov-Bohm (AB) oscillations in the local density of states (LDOS) for topological insulator (TI) and conventional metal Au(111) surfaces with spin-orbit interaction, which can be probed by spin-polarized scanning tunneling microscopy. We show that the spacial AB oscillatory period in the total LDOS is a flux quantum $\Phi_{0}\mathtt{=}hc/e$ (weak localization) in both systems. Remarkably, an analogous weak antilocalization with $\Phi_{0}/2$ periodic spacial AB oscillations in spin components of LDOS for TI surface is observed, while it is absent in Au(111).Comment: 4 APL pages, 3 figure

Quantum Corrals and Quantum Mirages on the Surface of a Topological Insulator

We study quantum corrals on the surface of a topological insulator (TI). Different resonance states induced by nonmagnetic (NM), antiferromagnetic (AFM), and ferromagnetic (FM) corrals are found. Intriguingly, the spin is clearly energy-resolved in a FM corral, which can be effectively used to operate surface carrier spins of TI. We also show that an observable quantum mirage of a magnetic impurity can be projected from the occupied into the empty focus of a FM elliptic corral, while in NM and AFM corrals the mirage signal becomes negligibly weak. In addition, the modulation of the interaction between two magnetic impurities in the quantum corrals is demonstrated. These prominent effects may be measured by spin-polarized STM experiments.Comment: 5 PRB pages, 4 figure

Multiple scattering theory of quasiparticles on a topological insulator surface

A general partial-wave multiple scattering theory for scattering from cylindrically symmetric potentials on a topological insulator (TI) surface is developed. As an application, the cross sections for a single scatterer and two scatterers are discussed. We find that the symmetry of differential cross section is reduced and the backscattering is allowed for massive Dirac fermions on gapped TI surface. Remarkably, a sharp resonance peak at the band edge of the gapped TI is found in the total cross section $\Lambda_{tot}$, which may offer a useful way to determine the gap (as well as the effective mass of quasiparticles) on TI surface. We show that the interference effect is obvious in cross sections during the quasiparticle scattering between the scatterer pair, and additional resonance peaks are introduced in $\Lambda_{tot}$ when the higher partial waves are taken into account.Comment: 10 pages, 3 figure

4,5,6,7-Tetra­chloro-N-(2-fluoro­phen­yl)phthalimide

In the title compound, C14H4Cl4FNO2, the benzene ring and the phthalimide plane are nearly planar, the maximum deviations being 0.005 (2) and 0.010 (2) Å, respectively, but the mol­ecule as a whole is not planar: the dihedral angle between the two planar ring systems is 68.06 (10)°. A short Cl⋯O contact of 2.914 (2) Å exists in the crystal structure

Quasiparticle states and quantum interference induce by magnetic impurities on a two-dimensional topological superconductor

We theoretically study the effect of localized magnetic impurities on two-dimensional topological superconductor (TSC). We show that the local density of states (LDOS) can be tuned by the effective exchange field $m$, the chemical potential $\mu$ of TSC, and the distance $\Delta r$ as well as relative spin angle $\alpha$ between two impurities. The changes in $\Delta r$ between two impurities alter the interference and result in significant modifications to the bonding and antibonding states. Furthermore, the bound-state spin LDOS induced by single and double magnetic impurity scattering, the quantum corrals, and the quantum mirages are also discussed. Finally, we briefly compare the impurities in TSC with those in topological insulators.Comment: J. Phys.: Condens. Matter 24, 145502 (2012

Bis(1H-benzimidazole-κN 3)bis­[2-(naphthalen-1-yl)acetato-κ2 O,O′]manganese(II) monohydrate

In the title compound, [Mn(C12H9O2)2(C7H6N2)2]·H2O, the MnII ion is located on a twofold rotation axis and six-coordinated, displaying a distorted MnN2O4 octa­hedral geometry. The crystal packing is stabilized by N—H⋯O hydrogen bonds, which give rise to a one-dimensional structure along [001], and π–π inter­actions between the imidazole rings and between the benzene rings of the 2-(naphthalen-1-yl)acetate ligands [centroid–centroid distances = 3.761 (3) and 3.728 (4) Å]. The contribution of the electron density associated with the disordered water molecules was not considerd in the final structure model

4,5,6,7-Tetra­chloro-2-(4-fluoro­phen­yl)isoindoline-1,3-dione

The title compound, C14H4Cl4FNO2, has crystallographic twofold symmetry with the N and F atoms and two C atoms of the benzene ring located on a twofold rotation axis. The isoindole­dione ring system is almost planar [maximum atomic deviation = 0.036 (3) Å], and is twisted with respect to the florobenzene ring, making a dihedral angle of 58.56 (16)°. Weak inter­molecular C—H⋯Cl hydrogen bonding is present in the crystal structure

4,5,6,7-Tetra­chloro-2-(2,2,2-trifluoro­eth­yl)isoindoline-1,3-dione

In the title compound, C10H2Cl4F3NO2, the isoindoline ring system is almostplanar, the maximum atomic deviation being 0.064 (2) Å. The C—C bond of the ethyl­ene group is twisted with respect to the isoindoline plane by a dihedral angle of 59.58 (12)°. In the crystal, weak inter­molecular C—H⋯F hydrogen bonding links the mol­ecules into supra­molecular chains running along the a axis. A short inter­molecular Cl⋯O contact of 2.950 (3) Å is also observed