103 research outputs found
Measurable entanglement
Amount of entanglement carried by a quantum bipartite state is usually
evaluated in terms of concurrence (see Ref. 1). We give a physical
interpretation of concurrence that reveals a way of its direct measurement and
discuss possible generalizations.Comment: 3 pages, submitted to Applied Physics Letter
Quantification of entanglement via uncertainties
We show that entanglement of pure multi-party states can be quantified by
means of quantum uncertainties of certain basic observables through the use of
measure that has been initially proposed in [10] for bipartite systems.Comment: Changed content, references added 7 pages, no figures, PRA in pres
On the phase transition of light in cavity QED lattices
Systems of strongly interacting atoms and photons, that can be realized
wiring up individual cavity QED systems into lattices, are perceived as a new
platform for quantum simulation. While sharing important properties with other
systems of interacting quantum particles here we argue that the nature of
light-matter interaction gives rise to unique features with no analogs in
condensed matter or atomic physics setups. By discussing the physics of a
lattice model of delocalized photons coupled locally with two-level systems
through the elementary light-matter interaction described by the Rabi model, we
argue that the inclusion of counter rotating terms, so far neglected, is
crucial to stabilize finite-density quantum phases of correlated photons out of
the vacuum, with no need for an artificially engineered chemical potential. We
show that the competition between photon delocalization and Rabi non-linearity
drives the system across a novel parity symmetry-breaking quantum
criticality between two gapped phases which shares similarities with the Dicke
transition of quantum optics and the Ising critical point of quantum magnetism.
We discuss the phase diagram as well as the low-energy excitation spectrum and
present analytic estimates for critical quantities.Comment: 5+3 pages, published versio
Multipliers on some weighted L
Let G be a locally compact abelian group with Haar measure
dx, and let ω be a symmetric Beurling weight function on G (Reiter, 1968). In this paper, using the relations between
pi and qi, where 1<pi, qi<∞,pi≠qi(i=1,2), we show that the space of multipliers from
Lωp(G) to the space S(q′1,q′2,ω−1), the space of multipliers from Lωp1(G)∩Lωp2(G) to Lωq(G) and the space of
multipliers Lωp1(G)∩Lωp2(G) to
S(q′1,q′2,ω−1)
Quantum entanglement of spin-1 bosons with coupled ground states in optical lattices
We examine particle entanglement, characterized by pseudo-spin squeezing, of
spin-1 bosonic atoms with coupled ground states in a one-dimensional optical
lattice. Both the superfluid and Mott-insulator phases are investigated
separately for ferromagnetic and antiferromagnetic interactions. Mode
entanglement is also discussed in the Mott insulating phase. The role of a
small but nonzero angle between the polarization vectors of counter-propagating
lasers forming the optical lattice on quantum correlations is investigated as
well.Comment: 18 pages, 8 figures. To be published in Journal of Physics
Protein folding rates correlate with heterogeneity of folding mechanism
By observing trends in the folding kinetics of experimental 2-state proteins
at their transition midpoints, and by observing trends in the barrier heights
of numerous simulations of coarse grained, C-alpha model, Go proteins, we show
that folding rates correlate with the degree of heterogeneity in the formation
of native contacts. Statistically significant correlations are observed between
folding rates and measures of heterogeneity inherent in the native topology, as
well as between rates and the variance in the distribution of either
experimentally measured or simulated phi-values.Comment: 11 pages, 3 figures, 1 tabl
Optimal bundle formation and pricing of two products with limited stock
In this study, we consider the stochastic modeling of a retail firm that sells two types of perishable products in a single period not only as independent items but also as a bundle. Our emphasis is on understanding the bundling practices on the inventory and pricing decisions of the firm. One of the issues we address is to decide on the number of bundles to be formed from the initial product inventory levels and the price of the bundle to maximize the expected profit. Product demands follow a Poisson Process with a price dependent rate. Customer reservation prices are assumed to have a joint distribution. We study the impact of reservation price distributions, initial inventory levels, product prices, demand arrival rates and cost of bundling. We observe that the expected profit decreases as the correlation between the reservation prices of two products increases. With negative correlation, bundling cost has a significant impact on the number of bundles formed. When the product prices are low, the retailer sells individual products as well as the bundle (mixed bundling), when they are high, the retailer sells only bundles (pure bundling). The expected profit and the number of bundles offered decrease as the variance of the reservation price distribution increases. For high starting inventory levels, the retailer reduces bundle price and offers more bundles. The number of bundle sales decreases and the number of individual product sales increases when the arrival rate increases since the need for bundling decreases. Impacts of substitutability and complementarity of products are also investigated. The retailer forms more bundles, or charges higher prices for the bundle or both as the products become more complementary and less substitutable. © 2009 Elsevier B.V. All rights reserved
MHD thermogravitational convection and thermal radiation of a micropolar nanoliquid in a porous chamber
This work studies the thermogravitational transmission and thermal radiation of micropolar nanoliquid within
Raman superradiance and spin lattice of ultracold atoms in optical cavities
We investigate synthesis of a hyperfine spin lattice in an atomic
Bose-Einstein condensate, with two hyperfine spin components, inside a
one-dimensional high-finesse optical cavity, using off-resonant superradiant
Raman scattering. Spatio-temporal evolution of the relative population of the
hyperfine spin modes is examined numerically by solving the coupled
cavity-condensate mean field equations in the dispersive regime. We find,
analytically and numerically, that beyond a certain threshold of the transverse
laser pump, Raman superradiance and self-organization of the hyperfine spin
components simultaneously occur and as a result a magnetic lattice is formed.
The effects of an extra laser pump parallel to the cavity axis and the
time-dependence of the pump strength on the synthesis of a sharper lattice are
also addressed.Comment: Accepted for publication in New Journal of Physics. 16 pages and 6
figure
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