8,396 research outputs found
Stripe Formation in Fermionic Atoms on 2-D Optical Lattice inside a Box Trap: DMRG Studies for Repulsive Hubbard Model with Open Boundary Condition
We suggest that box shape trap enables to observe intrinsic properties of the
repulsive Hubbard model in a fixed doping in contrast to the harmonic trap
bringing about spatial variations of atom density profiles. In order to predict
atomic density profile under the box trap, we apply the directly-extended
density-matrix renormalization group method to 4-leg repulsive Hubbard model
with the open boundary condition. Consequently, we find that stripe formation
is universal in a low hole doping range and the stripe sensitively changes its
structure with variations of and the doping rate. A remarkable change is
that a stripe formed by a hole pair turns to one by a bi-hole pair when
entering a limited strong range. Furthermore, a systematic calculation
reveals that the Hubbard model shows a change from the stripe to the Friedel
like oscillation with increasing the doping rate
Modified Reconstruction of Standard Model in Non-Commutative Differential Geometry
Sogami recently proposed the new idea to express Higgs particle as a kind of
gauge particle by prescribing the generalized covariant derivative with gauge
and Higgs fields operating on quark and lepton fields. The field strengths for
both the gauge and Higgs fields are defined by the commutators of the covariant
derivative by which he could obtain the Yang-Mills Higgs Lagrangian in the
standard model. Inspired by Sogami's work, we present a modification of our
previous scheme to formulate the spontaneously broken gauge theory in
non-commutative geometry on the discrete space; Minkowski space multiplied by
two points space by introducing the generation mixing matrix in operation of
the generalized derivative on the more fundamental fields a_i(x,y) which
compose the gauge and Higgs fields. The standard model is reconstructed
according to the modified scheme, which does not yields not only any special
relations between the particle masses but also the special restriction on the
Higgs potential.Comment: 21 page
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