Phase space measure concentration for an ideal gas

We point out that a special case of an ideal gas exhibits concentration of the volume of its phase space, which is a sphere, around its equator in the thermodynamic limit. The rate of approach to the thermodynamic limit is determined. Our argument relies on the spherical isoperimetric inequality of L\'{e}vy and Gromov.Comment: 15 pages, No figures, Accepted by Modern Physics Letters

Quantum logic gates using Stark shifted Raman transitions in a cavity

We present a scheme to realise the basic two-quibit logic gates such as quantum phase gate and controlle-NOT gate using a detuned optical cavity interacting with a three-level Raman system. We discuss the role of Stark shifts which are as important as the terms leading to two-photon transition. The operation of the proposed logic gates involves metastable states of the atom and hence is not affected by spontaneous emission. These ideas can be extended to produce multiparticle entanglement.Comment: 5 pages, 1 figure, RevTeX4, Text is modifie

Rate of parity violation from measure concentration

We present a geometric argument determining the kinematic (phase-space) factor contributing to the relative rate at which degrees of freedom of one chirality come to dominate over degrees of freedom of opposite chirality, in models with parity violation. We rely on the measure concentration of a subset of a Euclidean cube which is controlled by an isoperimetric inequality. We provide an interpretation of this result in terms of ideas of Statistical Mechanics.Comment: 10 pages, no figure

Topologically decoherence-protected qubits with trapped ions

We show that trapped ions can be used to simulate a highly symmetrical Hamiltonian with eingenstates naturally protected against local sources of decoherence. This Hamiltonian involves long range coupling between particles and provides a more efficient protection than nearest neighbor models discussed in previous works. Our results open the perspective of experimentally realizing in controlled atomic systems, complex entangled states with decoherence times up to nine orders of magnitude longer than isolated quantum systems.Comment: 4 page

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)

A note using mergers and acquisitions to gain competitive advantage in the United States in the case of Latin American MNCs

Author's OriginalThe "new" economic and business climate in Latin America, fostered by multilateral trade agreements such as NAFTA, MERCOSUR, and the ANDEAN Pact, suggests that Latin American (LA) firms must become more aggressive and competitive in order to survive. Foreign direct investment in the form of mergers and acquisitions (M&A) is often an effective way of competing in a tough global environment. Using transactions data collected from Security Data Company's Worldwide Merger and Acquisition database, this paper analyzes the relative involvement of firms from five LA countries (Argentina, Brazil, Chile, Mexico, and Venezuela) in acquiring targets in the United States of America. Transaction characteristics examined and summarized include the annual distribution (1985-1998) of the deals, the industrial sector of the target firm, the form of acquisition method used, and the form of ownership of the target firm. The trends are analyzed, and implications for managers are indicated.Milman, C. D., D’Mello, J. P., Aybar, B., & Arbaláez, H. (2001). A note using mergers and acquisitions to gain competitive advantage in the United States in the case of Latin American MNCs. International Review of Financial Analysis, 10(3), 323-332. doi:10.1016/S1057-5219(01)00056-