10,883 research outputs found
Charge and Statistics of Quasiparticles in Fractional Quantum Hall Effec
We have studied here the charge and statistics of quasiparticle excitations
in FQH states on the basis of the Berry phase approach incorporating the fact
that even number of flux quanta can be gauged away when the Berry phase is
removed to the dynamical phase. It is observed that the charge and
statistical parameter of a quasiparticle at filling factor
are given by and
, with the fact that the charge of the quasihole is
opposite to that of the quasielectron. Using Laughlin wave function for
quasiparticles, numerical studies have been done following the work of
Kj{\o}nsberg and Myrheim \cite{KM} for FQH states at and it is
pointed out that as in case of quasiholes, the statistics parameter can be well
defined for quasielectrons having the value .Comment: 12 pages, 4 figure
Relation between concurrence and Berry phase of an entangled state of two spin 1/2 particles
We have studied here the influence of the Berry phase generated due to a
cyclic evolution of an entangled state of two spin 1/2 particles. It is shown
that the measure of formation of entanglement is related to the cyclic
geometric phase of the individual spins. \\Comment: 6 pages. Accepted in Europhys. Letters (likely to be published in vol
73, pp1-6 (2006)
Topological Aspect of high- Superconductivity, Fractional Quantum Hall Effect and Berry Phase
We have analysed here the equivalence of RVB states with FQH states
in terms of the Berry Phase which is associated with the chiral anomaly in 3+1
dimensions. It is observed that the 3-dimensional spinons and holons are
characterised by the non-Abelian Berry phase and these reduce to 1/2 fractional
statistics when the motion is confined to the equatorial planes. The
topological mechanism of superconductivity is analogous to the topological
aspects of fractional quantum Hall effect with .Comment: 12 pages latex fil
Magnus Force on Quantum Hall Skyrmions and Vortices
We have discussed here the Magnus force acting on the vortices and skyrmions
in the quantum Hall systems. We have found that it is generated by the
chirality of the system which is associated with the Berry phase and is same
for both the cases.Comment: 5 page
High Superconductivity, Skyrmions and the Berry Phase
It is here pointed out that the antiferromagnetic spin fluctuation may be
associated with a gauge field which gives rise to the antiferromagnetic ground
state chirality. This is associated with the chiral anomaly and Berry phase
when we consider the two dimensional spin system on the surface of a 3D sphere
with a monopole at the centre. This realizes the RVB state where spinons and
holons can be understood as chargeless spins and spinless holes attached with
magnetic flux. The attachment of the magnetic flux of the charge carrier
suggest, that this may be viewed as a skyrmion. The interaction of a massless
fermion representing a neutral spin with a gauge field along with the
interaction of a spinless hole with the gauge field enhances the
antiferromagnetic correlation along with the pseudogap at the underdoped
region. As the doping increases the antiferromagnetic long range order
disappears for the critical doping parameter . In this framework,
the superconducting pairing may be viewed as caused by skyrmion-skyrmion bound
states.Comment: 10 pages, accepted in Phys. Rev.
Large fragmentation phenomena in relativistic Au + Al interactions
A stack consisting of CR39 plastics and Al target has been exposed to 1.015 GeV/n Au beamat an angle of 30 from LBL BEVALAC. About 5499 cone lengths of the Au beam and their fragments have been optically measured fromthe etched plastics kept below the Al target and the estimated partial cross-sections of large fragments for charges ZF ranging from 75 to 78 have been found comparable with the expected
results from the semi-empirical model of Silberberg and Tsao. But those values are above the expected results from the abrasion-ablation model of Townsend et al. The
observed charge pick-up cross-section for Z = +1 is found to lie below the global fit to the charge pick-up
cross-section results surveyed by Westphal et al
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