3,977 research outputs found
Pneumocystis pneumonia complicated with pneumothorax, pneumomediastinum and subcutaneous emphysema
info:eu-repo/semantics/publishedVersio
Feasibility of approximating spatial and local entanglement in long-range interacting systems using the extended Hubbard model
We investigate the extended Hubbard model as an approximation to the local
and spatial entanglement of a one-dimensional chain of nanostructures where the
particles interact via a long range interaction represented by a `soft' Coulomb
potential. In the process we design a protocol to calculate the
particle-particle spatial entanglement for the Hubbard model and show that, in
striking contrast with the loss of spatial degrees of freedom, the predictions
are reasonably accurate. We also compare results for the local entanglement
with previous results found using a contact interaction (PRA, 81 (2010) 052321)
and show that while the extended Hubbard model recovers a better agreement with
the entanglement of a long-range interacting system, there remain realistic
parameter regions where it fails to predict the quantitative and qualitative
behaviour of the entanglement in the nanostructure system.Comment: 6 pages, 5 figures and 1 table; added results with correlated hopping
term; accepted by EP
Universal and deterministic manipulation of the quantum state of harmonic oscillators: a route to unitary gates for Fock State qubits
We present a simple quantum circuit that allows for the universal and
deterministic manipulation of the quantum state of confined harmonic
oscillators. The scheme is based on the selective interactions of the referred
oscillator with an auxiliary three-level system and a classical external
driving source, and enables any unitary operations on Fock states, two-by-two.
One circuit is equivalent to a single qubit unitary logical gate on Fock states
qubits. Sequences of similar protocols allow for complete, deterministic and
state-independent manipulation of the harmonic oscillator quantum state.Comment: 4 pages, 4 figure
Hubbard model as an approximation to the entanglement in nanostructures
We investigate how well the one-dimensional Hubbard model describes the entanglement of particles trapped in a string of quantum wells. We calculate the average single-site entanglement for two particles interacting via a contact interaction and consider the effect of varying the interaction strength and the interwell distance. We compare the results with the ones obtained within the one-dimensional Hubbard model with on-site interaction. We suggest an upper bound for the average single-site entanglement for two electrons in M wells and discuss analytical limits for very large repulsive and attractive interactions. We investigate how the interplay between interaction and potential shape in the quantum-well system dictates the position and size of the entanglement maxima and the agreement with the theoretical limits. Finally, we calculate the spatial entanglement for the quantum-well system and compare it to its average single-site entanglement
Subacute Hypophysitis with Panhypopituitarism as First Presentation of HIV and Syphilis Coinfection
Infection by Treponema pallidum still represents a clinical challenge due to its various forms of presentation. HIV coinfection added diversity and changed the natural history of syphilis as a systemic infection. We present a rare case of subacute hypophysitis and panhypopituitarism due to an early active neurosyphilis in a previously unknown HIV coinfected patient.info:eu-repo/semantics/publishedVersio
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