915 research outputs found
Z_2 Monopoles, Vortices and the Universality of the SU(2) Deconfinement Transition
We investigate the effect of magnetic monopoles and vortices on the
finite temperature deconfinement phase transition in the fundamental - adjoint
SU(2) lattice gauge theory. In the limit of complete suppression of the
monopoles, the mixed action for the SU(2) theory in its Villain form is shown
to be self-dual under the exchange of the fundamental and adjoint couplings. By
further suppressing the vortices we show that the extended model reduces
to the Wilson action with a modified coupling. The universality of the SU(2)
deconfinement phase transition with the Ising model is therefore expected to
remain intact in the entire plane of the fundamental-adjoint couplings in the
continuum limit. The self-duality arguments related to the suppression of
monopoles are also applicable to the Villain form of mixed action for the SU(N)
theory with magnetic monopoles.Comment: 12 pages, Latex, To appear in Phys. Lett.
Non-Destructive Discrimination of arbitrary set of orthogonal quantum states by NMR using Quantum Phase Estimation
An algorithm based on quantum phase estimation, which discriminates quantum
states nondestructively within a set of arbitrary orthogonal states, is
described and experimentally verified by a NMR quantum information processor.
The procedure is scalable and can be applied to any set of orthogonal states.
Scalability is demonstrated through Matlab simulation
More On The SU(2) Deconfinement Transition In The Mixed Action
We examine certain issues related to the universality of the SU(2) lattice
gauge theory at non-zero temperatures. Using Monte Carlo simulations and strong
coupling expansions, we study the behavior of the deconfinement transition in
an extended coupling plane (beta, beta_A) around the tricritical point where
the deconfinement transition changes from second to first order. Our numerical
results on N_tau =2,4,6,8 lattices show that the tricritical point first moves
down towards the Wilson axis and and then moves slowly upwards, if at all, as
the lattice spacing is reduced. Lattices with very large N_tau seem to be
therefore necessary for the mixed action to exhibit the critical exponents of
the three dimensional Ising model for positive values of the adjoint coupling.Comment: LaTeX, 35 Pages including 8 Postscript Figures, Final version to be
published in Phys. Rev. D, Title changed in the journal, Additional results
on larger lattices presented which change somewhat our earlier conclusions.
Added a reference and 4 figure
Singlet state creation and Universal quantum computation in NMR using Genetic Algorithm
Experimental implementation of a quantum algorithm requires unitary operator
decomposition. Here we treat the unitary operator decomposition as an
optimization problem and use Genetic Algorithm, a global optimization method
inspired by nature's evolutionary process for operator decomposition. As an
application, we apply this to NMR Quantum Information Processing and find a
probabilistic way of doing universal quantum computation using global hard
pulses. We also demonstrate efficient creation of singlet state (as a special
case of Bell state) directly from thermal equilibrium using an optimum sequence
of pulses
A differential memristive synapse circuit for on-line learning in neuromorphic computing systems
Spike-based learning with memristive devices in neuromorphic computing
architectures typically uses learning circuits that require overlapping pulses
from pre- and post-synaptic nodes. This imposes severe constraints on the
length of the pulses transmitted in the network, and on the network's
throughput. Furthermore, most of these circuits do not decouple the currents
flowing through memristive devices from the one stimulating the target neuron.
This can be a problem when using devices with high conductance values, because
of the resulting large currents. In this paper we propose a novel circuit that
decouples the current produced by the memristive device from the one used to
stimulate the post-synaptic neuron, by using a novel differential scheme based
on the Gilbert normalizer circuit. We show how this circuit is useful for
reducing the effect of variability in the memristive devices, and how it is
ideally suited for spike-based learning mechanisms that do not require
overlapping pre- and post-synaptic pulses. We demonstrate the features of the
proposed synapse circuit with SPICE simulations, and validate its learning
properties with high-level behavioral network simulations which use a
stochastic gradient descent learning rule in two classification tasks.Comment: 18 Pages main text, 9 pages of supplementary text, 19 figures.
Patente
Examining the Kalburgi thesis on the origin of the Lingayats
The story of the origin of the Lingayats, and the current demand of the community seeking minority status, lies in the late M. M. Kalburgi's thesis. Manu V. Devadevan explores the thesis and cautions against the historical claims made as part of the current demand for minority status
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