118 research outputs found
Condensate Fraction and Pair Coherence Lengths of Two-Dimension Fermi Gases with Spin-Orbit Coupling
The effects of Rashba spin-orbit coupling on BCS-BEC crossover, the
condensate fraction and pair coherence lengths for a two-component attractive
Fermi gas in two dimension are studied. The results at indicate that (1)
when the strength of SOC is beyond a critical value, BCS-BEC crossover does not
happen in a conventional sense; (2) SOC enhances the condensate fraction, but
suppresses pair coherence lengths
BCS-BEC Crossover in Mix-dimensional Fermi Gases
We investigate a mix-dimensional Fermi-Fermi mixture in which one species is
confined in two-dimensional(2D) space while the other is free in
three-dimensional space(3D). We determine the superfluid transition temperature
for the entire BCS-BEC crossover including the important effects of
noncondensed pairs. We find that the transition temperature reduces while the
imbalance of mass is increased or lattice constant () is reduced. In
population imbalance case, the stability of superfluid is sharply destroyed by
increasing the polarization.Comment: 7 pages, 5 figure
A New Non-Abelian Topological Phase of Cold Fermi Gases in Anisotropic and Spin-Dependent Optical Lattices
To realize non-Abelian s-wave topological superfluid (TS) of cold Fermi
gases, generally a Zeeman magnetic field larger than superfluid pairing gap is
necessary. In this paper we find that using an anisotropic and spin-dependent
optical lattice (ASDOL) to trap gases, a new non-Abelian TS phase appears, in
contrast to an isotropic and spin-independent optical lattice. A characteristic
of this new non-Abelian TS is that Zeeman magnetic field can be smaller than
the superfluid pairing gap. By self-consistently solving pairing gap equation
and considering the competition against normal state and phase separation, this
new phase is also stable. Thus an ASDOL supplies a convenient route to realize
TS. We also investigate edge states and the effects of a harmonic trap
potential
Modeling Multi-wavelength Pulse Profiles of Millisecond Pulsar PSR B1821-24
PSR B182124 is a solitary millisecond pulsar (MSP) which radiates
multi-wavelength pulsed photons. It has complex radio, X-ray and -ray
pulse profiles with distinct peak phase-separations that challenge the
traditional caustic emission models. Using the single-pole annular gap model
with suitable magnetic inclination angle () and viewing angle
(), we managed to reproduce its pulse profiles of three
wavebands. It is found that the middle radio peak is originated from the core
gap region at high altitudes, and the other two radio peaks are originated from
the annular gap region at relatively low altitudes. Two peaks of both X-ray and
-ray wavebands are fundamentally originated from annular gap region,
while the -ray emission generated from the core gap region contributes
somewhat to the first -ray peak. Precisely reproducing the
multi-wavelength pulse profiles of PSR B182124 enables us to understand
emission regions of distinct wavebands and justify pulsar emission models.Comment: Accepted for publication in Ap
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