Separability Criteria and Entanglement Measures for Pure States of N Identical Fermions

The study of the entanglement properties of systems of N fermions has attracted considerable interest during the last few years. Various separability criteria for pure states of N identical fermions have been recently discussed but, excepting the case of two-fermions systems, these criteria are difficult to implement and of limited value from the practical point of view. Here we advance simple necessary and sufficient separability criteria for pure states of N identical fermions. We found that to be identified as separable a state has to comply with one single identity involving either the purity or the von Neumann entropy of the single-particle reduced density matrix. These criteria, based on the verification of only one identity, are drastically simpler than the criteria discussed in the recent literature. We also derive two inequalities verified respectively by the purity and the entropy of the single particle, reduced density matrix, that lead to natural entanglement measures for N-fermion pure states. Our present considerations are related to some classical results from the Hartree-Fock theory, which are here discussed from a different point of view in order to clarify some important points concerning the separability of fermionic pure states.Comment: 6 pages, 0 figure

Resultados de pesquisa em alimentação com eqüinos da raça Árabe na UEPAE de São Carlos, SP.

O trabalho visava a substituição do arracoamento tradicional (AT) isto é, o fornecimento de concentrado e volumosos duas vezes ao dia por uma ração peletizada (RCP), três vezes ao dia, nos mesmos horários.bitstream/CPPSE/10499/1/PROCIComT2AM1987.00049.pd

Alimentação de cavalos Árabes na Fazenda Canchim.

Há alguns anos a alimentação dos eqüinos vem entrando em fase de grande progresso tecnológico, melhorando e se tornando mais econômico. Alimentação de cavalos Árabes na Fazenda Canchim.bitstream/item/121689/1/PROCI-1978.0000.pd

Alimentação de equinos da raça Árabe.

Como o objetivo de levar aos produtores solucoes eficientes e economicas para os inumeros problemas dentro da alimentacao, foi iniciado, 1975, um trabalho de que visava a substituicao do arracoamento tradicional(TA), isto e o fornecimento de concentrado e de volumoso duas vezes ao dia (7:00 horas 1/2 concentrado; 13:00 horas 1/2 concentrado e 1/3 volumoso e 17:00 horas 2/3 volumoso) por uma racao completa peletizada (RCP), tres vezes ao dia, no mesmo horario. A racao utilizada era constituida de 60% de feno + alfafa + 34% milho e 6% farelo de soja. Este tipo de arracoamento (RCP), elimina uma serie de inconvinientes, tais como: corte diario de verde; disperdicio da ordem de 20% de feno, quando fornecido nas baias.bitstream/item/121119/1/digitalizar0006.pd

Pesquisa analítica e sistêmica em alimentação de bovinos e seus resultados na intensificação de sistemas de produção.

Resultados de pesquisa analítica; Interação genótipo ambiente; Alimentos e confinamento; Resultados de pesquisa sistêmica.Rsumo expandido

Exponential Temperature Dependence of Penetration Depth in Single Crystal MgB_2

The temperature dependence of the London penetration depth,lambda(T), was measured in both single crystal and polycrystalline MgB_2 samples by a high-resolution, radio frequency technique. A clear exponential temperature dependence of lambda(T) was observed at low temperature, indicating s-wave pairing. A BCS fit to the lowest temperature data gives an in-plane energy gap Delta of 2.6\pm0.2 meV (2\Delta/T_c=1.5\pm0.1), which is significantly smaller than the standard BCS weak coupling value of 3.5. We find that the data are best described by a two-gap model.Comment: Minor corrections added, as per published articl

Selenoxopropadienylidene (CCCSe) as a bridging ligand

The reaction of [W(≡CC≡CSiMe3)(CO)2(Tp*)] (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with [nBu4N]F and selenium in the presence of [RuCl(PPh3)2(η-C5H5)] affords a mixture of the tricarbido complex [WRu(μ-CCC)(CO)2(PPh3)2(η-C5H5)(Tp*)] and the selenoxopropadienylidene (C3Se) complex [WRu(μ-CCCSe)(CO)2(PPh3)2(η-C5H5)(Tp*)], both of which were structurally characterized. The formation of the bimetallic C3Se complex is consistent with the intermediacy of the salt [nBu4N] [W(≡CC≡CSe)(CO)2(Tp*)], which could be observed spectroscopically and computationally interrogated, but not yet isolated.This work was supported by the Australian Research Council (DP130102598 and DP110101611)