30,704 research outputs found
Rayleigh-Brillouin scattering of carbon dioxide
The spectral lineshape of spontaneous Rayleigh-Brillouin scattering in CO2 is
studied in a range of pressures. The spectrum is influenced by the bulk
viscosity, which is a relaxation phenomenon involving the internal degrees of
freedom of the molecule. The associated relaxation rates can be compared to the
frequency shift of the scattered light, which demands precise measurements of
the spectral lineshape. We find the value of the bulk viscosity around 5.7 X
10^{-6} kg/(ms) for the range of pressures p= 2-4 bar and for conditions of
room temperature
Non-Abelian Quantum Hall Effect in Topological Flat Bands
Inspired by recent theoretical discovery of robust fractional topological
phases without a magnetic field, we search for the non-Abelian quantum Hall
effect (NA-QHE) in lattice models with topological flat bands (TFBs). Through
extensive numerical studies on the Haldane model with three-body hard-core
bosons loaded into a TFB, we find convincing numerical evidence of a stable
bosonic NA-QHE, with the characteristic three-fold quasi-degeneracy of
ground states on a torus, a quantized Chern number, and a robust spectrum gap.
Moreover, the spectrum for two-quasihole states also shows a finite energy gap,
with the number of states in the lower energy sector satisfying the same
counting rule as the Moore-Read Pfaffian state.Comment: 5 pages, 7 figure
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