31,121 research outputs found
Bright solitons in asymmetrically trapped Bose-Einstein condensate
We study the dynamics of bright solitons in a Bose-Einstein condensate (BEC)
confined in a highly asymmetric trap. While working within the f ramework of a
variational approach we carry out the stability analysis o f BEC solitons
against collapse. When the number of atoms in the soliton exceeds a critical
number , it undergoes the so called primary col lapse. We find an
analytical expression for in terms of appropriat e experimental
quantities that are used to produce and confine the conde nsate. We further
demonstrate that, in the geometry of the problem consi dered, the width of the
soliton varies inversely as the number of consti tuent atoms.Comment: 5 pages, 1 figure
Contrasting the magnetic response between magnetic-glass and reentrant spin-glass
Magnetic-glass is a recently identified phenomenon in various classes of
magnetic systems undergoing a first order magnetic phase transition. We shall
highlight here a few experimentally determined characteristics of
magnetic-glass and the relevant set of experiments, which will enable to
distinguish a magnetic-glass unequivocally from the well known phenomena of
spin-glass and reentrant spin-glass.Comment: 10 pages and 4 figures. The preprint has been amended after taking
care of various typographical errors, some errors in Figs.2 and 4 and with
the addition of some new references. This version has been accepted for
publication in Physical Review
Kinetic arrest of the first order ferromagnetic to antiferromagnetic transition in Ce(FeRu) : formation of a magnetic-glass
We present results of dc magnetization and magnetic relaxation study showing
the kinetic arrest of a first order ferromagnetic to antiferromagnetic
transition in Ce(FeRu). This leads to the formation of a
non-ergodic glass-like magnetic state. The onset of the magnetic-glass
transformation is tracked through the slowing down of the magnetization
dynamics. This glassy state is formed with the assistance of an external
magnetic field and this is distinctly different from the well known
'spin-glass' state.Comment: 10 pages of text and 4 figure
Truncated Harmonic Osillator and Parasupersymmetric Quantum Mechanics
We discuss in detail the parasupersymmetric quantum mechanics of arbitrary
order where the parasupersymmetry is between the normal bosons and those
corresponding to the truncated harmonic oscillator. We show that even though
the parasusy algebra is different from that of the usual parasusy quantum
mechanics, still the consequences of the two are identical. We further show
that the parasupersymmetric quantum mechanics of arbitrary order p can also be
rewritten in terms of p supercharges (i.e. all of which obey ).
However, the Hamiltonian cannot be expressed in a simple form in terms of the p
supercharges except in a special case. A model of conformal parasupersymmetry
is also discussed and it is shown that in this case, the p supercharges, the p
conformal supercharges along with Hamiltonian H, conformal generator K and
dilatation generator D form a closed algebra.Comment: 9 page
- …