13,191 research outputs found
Topological-Fermi-Liquid to Quantum-Hall-Liquid Transitions: -Band and -Band Fermions in a Magnetic Field
We find that in a multi-orbital system with intraorbital and interorbital
hopping integrals, the Hall conductance exhibits various topological quantum
phase transitions (QPTs) induced by on-site orbital polarization: integer
quantum Hall (IQH) plateau transitions, and topological Fermi liquid to IQH
transitions. Such topological QPTs are demonstrated in two systems: a -band
spinless fermionic system realizable with ultracold atoms in optical lattice,
and a -band spinful fermionic system closely related to giant orbital Hall
effects in transition metals and their compounds.Comment: 4 pages, 4 figure
Effect of sea quarks on the single-spin asymmetries in polarized pp collisions at RHIC
We calculate the single-spin asymmetries of
bosons produced in polarized pp collisions with the valence part of the up and
down quark helicity distributions modeled by the light-cone
quark-spectator-diquark model while the sea part helicity distributions of the
up and down quarks treated as parametrization. Comparing our results with those
from experimental data at RHIC, we find that the helicity distributions of sea
quarks play an important role in the determination of the shapes of
. It is shown that is sensitive to , while to intuitively. The experimental
data of the polarized structure functions and the sum of helicities are also
important to constrain the sizes of quark helicity distributions both for the
sea part and the valence part of the nucleon.Comment: 19 latex pages, 5 figures, final version for publicatio
Edge States and Quantum Hall Effect in Graphene under a Modulated Magnetic Field
Graphene properties can be manipulated by a periodic potential. Based on the
tight-binding model, we study graphene under a one-dimensional (1D) modulated
magnetic field which contains both a uniform and a staggered component. New
chiral current-carrying edge states are generated at the interfaces where the
staggered component changes direction. These edge states lead to an unusual
integer quantum Hall effect (QHE) in graphene, which can be observed
experimentally by a standard four-terminal Hall measurement. When Zeeman spin
splitting is considered, a novel state is predicted where the electron edge
currents with opposite polarization propagate in the opposite directions at one
sample boundary, whereas propagate in the same directions at the other sample
boundary.Comment: 5 pages, 4 figure
- …