1,515 research outputs found
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 = periodic AB oscillations in
spin-resolved LDOS gradually transit into the 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 (weak localization) in
both systems. Remarkably, an analogous weak antilocalization with
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 , 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 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 , the
chemical potential of TSC, and the distance as well as
relative spin angle between two impurities. The changes in
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
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