22,967 research outputs found
Exotic Haldane Superfluid Phase of Soft-Core Bosons in Optical Lattices
We propose to realize an exotic Haldane superfluid (HSF) phase in an extended
Bose-Hubbard model on the two-leg ladder (i.e., a two-species mixture of
interacting bosons). The proposal is confirmed by means of large-scale quantum
Monte Carlo simulations, with a significant part of the ground-state phase
diagram being revealed. Most remarkably, the newly discovered HSF phase
features both superfluidity and the non-local topological Haldane order. The
effects induced by varying the number of legs are furthermore explored. Our
results shed light on how topological superfluid emerges in bosonic systems.Comment: 5 pages, 6 figures; accepted for publication in Physical Review B
(April 29, 2016
Localization and compactness of Operators on Fock Spaces
For , let be the Fock space induced by a
weight function satisfying . In this
paper, given we introduce the concept of weakly localized
operators on , we characterize the compact operators in the
algebra generated by weakly localized operators. As an application, for
we prove that an operator in the algebra generated by bounded
Toeplitz operators with symbols is compact on if
and only if its Berezin transform satisfies certain vanishing property at
. In the classical Fock space, we extend the Axler-Zheng condition on
linear operators , which ensures is compact on for all
possible .Comment: 23 Page
Electron-doped phosphorene: A potential monolayer superconductor
We predict by first-principles calculations that the electron-doped
phosphorene is a potential BCS-like superconductor. The stretching modes at the
Brillouin-zone center are remarkably softened by the electron-doping, which
results in the strong electron-phonon coupling. The superconductivity can be
introduced by a doped electron density () above
cm, and may exist over the liquid helium temperature when cm. The maximum critical temperature is predicted to be
higher than 10 K. The superconductivity of phosphorene will significantly
broaden the applications of this novel material
Directionally asymmetric self-assembly of cadmium sulfide nanotubes using porous alumina nanoreactors: Need for chemohydrodynamic instability at the nanoscale
We explore nanoscale hydrodynamical effects on synthesis and self-assembly of
cadmium sulfide nanotubes oriented along one direction. These nanotubes are
synthesized by horizontal capillary flow of two different chemical reagents
from opposite directions through nanochannels of porous anodic alumina which
are used primarily as nanoreactors. We show that uneven flow of different
chemical precursors is responsible for directionally asymmetric growth of these
nanotubes. On the basis of structural observations using scanning electron
microscopy, we argue that chemohydrodynamic convective interfacial instability
of multicomponent liquid-liquid reactive interface is necessary for sustained
nucleation of these CdS nanotubes at the edges of these porous nanochannels
over several hours. However, our estimates clearly suggest that classical
hydrodynamics cannot account for the occurrence of such instabilities at these
small length scales. Therefore, we present a case which necessitates further
investigation and understanding of chemohydrodynamic fluid flow through
nanoconfined channels in order to explain the occurrence of such interfacial
instabilities at nanometer length scales.Comment: 26 pages, 6 figures; http://www.iiserpune.ac.in/researchhighlight
Nuclear modification factor in intermediate-energy heavy-ion collisions
The transverse momentum dependent nuclear modification factors (NMF), namely
, is investigated for protons produced in Au + Au at 1 GeV within
the framework of the isospin-dependent quantum molecular dynamics (IQMD) model.
It is found that the radial collective motion during the expansion stage
affects the NMF at low transverse momentum a lot. By fitting the transverse
mass spectra of protons with the distribution function from the Blast-Wave
model, the magnitude of radial flow can be extracted. After removing the
contribution from radial flow, the can be regarded as a thermal one
and is found to keep unitary at transverse momentum lower than 0.6 GeV/c and
enhance at higher transverse momentum, which can be attributed to Cronin
effect.Comment: 8 pages, 5 figures; aceepted by Physics Letters
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