493 research outputs found
Entanglement of formation for a class of -dimensional systems
Currently the entanglement of formation can be calculated analytically for
mixed states in a -dimensional Hilbert space. For states in higher
dimensional Hilbert space a closed formula for quantifying entanglement does
not exist. In this regard only entanglement bounds has been found for
estimating it. In this work, we find an analytical expression for evaluating
the entanglement of formation for bipartite ()-dimensional mixed
states.Comment: 5 pages, 4 figures. Submitted for publicatio
Lender of Last Resort and moral hazard
In this paper we revisit the Lender of Last Resort (LOLR) function of the central bank and the associated moral hazard incentives. We argue that, from an economic perspective, the strict application of penalties to the operation of LOLR actions can make that instrument unworkable. Instead, we suggest that both penalties and publication should only be applied after such LOLR had been in place for a time. Normative frameworks ought to be adjusted in this regard
Entanglement properties in the Inhomogeneous Tavis-Cummings model
In this work we study the properties of the atomic entanglement in the
eigenstates spectrum of the inhomogeneous Tavis-Cummings Model. The
inhomogeneity is present in the coupling among the atoms with quantum
electromagnetic field. We calculate analytical expressions for the concurrence
and we found that this exhibits a strong dependence on the inhomogeneity.Comment: 5 pages, 5 figure
Abrupt Changes in the Dynamics of Quantum Disentanglement
Entanglement evolution in high dimensional bipartite systems under
dissipation is studied. Discontinuities for the time derivative of the lower
bound of entanglement of formation is found depending on the initial conditions
for entangled states. This abrupt changes along the evolution appears as
precursors of entanglement sudden death.Comment: 4 pages and 6 figures, submitted for publicatio
Multipartite Entanglement Generation Assisted by Inhomogeneous Coupling
We show that controllable inhomogeneous coupling between two-level systems
and a common data bus provides a fast mechanism to produce multipartite
entanglement. Our proposal combines resonant interactions and engineering of
coupling strengths---between the qubits and the single mode---leading to well
defined entangled states. Furthermore, we show that, if the two-level systems
interact dispersively with the quantized mode, engineering of coupling
strengths allows the controlled access of the symmetric Hilbert space of
qubits.Comment: 5 pages, 4 figures. Submitted for publicatio
Sudden Birth Versus Sudden Death of Entanglement in Multipartite Systems
We study the entanglement dynamics of two cavities interacting with
independent reservoirs. Expectedly, we observe that, as the cavity entanglement
is depleted, it is transferred to the reservoir degrees of freedom. We find
that when the cavity entanglement suddenly disappear, the reservoir
entanglement suddenly and necessarily appears. Surprisingly, we show that this
{\it entanglement sudden birth} can manifest before, simultaneously, or even
after {\it entanglement sudden death}. Finally, we present an explanatory study
of other entanglement partitions and of higher dimensional systems.Comment: 5 pages, 5 figures, accepted for publication in Physical Review
Letter
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