25,550 research outputs found
Superfluidity and effective mass of magnetoexcitons in topological insulator bilayers: Effect of inter-Landau-level Coulomb interaction
The effective mass and superfluidity-normal phase transition temperature of
magnetoexcitons in topological insulator bilayers are theoretically
investigated. The intra-Landau-level Coulomb interaction is treated
perturbatively, from which the effective magnetoexciton mass is analytically
discussed. The inclusion of inter-Landau-level Coulomb interaction by more
exact numerical diagonalization of the Hamiltonian brings out important
modifications to magnetoexciton properties, which are specially characterized
by prominent reduction in the magnetoexciton effective mass and promotion in
the superfluidity-normal phase transition temperature at a wide range of
external parameters.Comment: 5.6 EPL pages, 4 figure
Two-Body Strong Decay of Z(3930) as the State
The new particle Z(3930) found by the Belle and BaBar Collaborations through
the process is identified to be the
state. Since the mass of this particle is above the threshold, the OZI-allowed two-body strong decays are the main
decay modes. In this paper, these strong decay modes are studied with two
methods. One is the instantaneous Bethe-Salpeter method within Mandelstam
formalism. The other is the combination of the model and the former
formalism. The total decay widths are 26.3 and 27.3 MeV for the methods with or
without the vertex, respectively. The ratio of over
which changes along with the mass of the initial meson
is also presented.Comment: 11 pages, 3 figure
Fractional quantum Hall effect of topological surface states under a strong tilted magnetic field
The fractional quantum Hall effect (FQHE) of topological surface-state
particles under a tilted strong magnetic field is theoretically studied by
using the exact diagonalization method. The Haldane's pseudopotentials for the
Coulomb interaction are analytically obtained. The results show that by
increasing the in-plane component of the tilted magnetic field, the FQHE state
at =0 Landau level (LL) becomes more stable, while the stabilities of
= LLs become weaker. Moreover, we find that the excitation gaps of the
FQHE states increase as the tilt angle is increased.Comment: 4.2 pages, 4 figure
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