61,739 research outputs found
On Locality of Schmidt-Correlated States
We review some results on the equivalence of quantum states under local
unitary transformations (LUT). In particular, the classification of two-qubit
Schmidt correlated (SC) states under LUT is investigated. By presenting the
standard form of quantum states under LUT, the sufficient and necessary
conditions of whether two different SC states are local unitary equivalent are
provided. The correlations of SC states are also discussed.Comment: 14 page
Complete Entanglement Witness for Quantum Teleportation
We propose a set of linear quantum entanglement witnesses constituted by
local quantum-mechanical observables with each two possible measurement
outcomes. These witnesses detect all the entangled resources which give rise to
a better fidelity than separable states in quantum teleportation and present
both sufficient and necessary conditions in experimentally detecting the useful
resources for quantum teleportation.Comment: 3 page
The fiscal framework and urban infrastructure finance in China
China has experienced more than 25 years of extraordinary economic growth. Underlying this growth has been a decentralized fiscal system, in which provinces and large cities are given the freedom to make infrastructure investmentsto stimulate local development, and are allowed to retain a large part of the fiscal revenues that are generated from economic activity. Although successful as a growth strategy, this policy created two problems for national fiscal management. First, it significantly reduced the central government's share of fiscal revenues, which fell from 34.8 percent in 1980 to 22 percent in 1992. Second, it widened economic and fiscal disparities between the rapidly growing urban coastal region and the rest of the country. Rapid growth in subnational debt (which rose 23-fold in a decade) and subnational nonperforming loans (estimated by the authors to range between US150 billion) has placed pressure on China's financial system. Traditionally, China has favored bank lending as a source of finance because the banking system has provided a vehicle for central political control over local debt. But as China's financial system matures, creditworthiness standards must become more important. The authors recommend greater use of the revenue streams from infrastructure assets as a financing source, and gradual relaxation of central political control over subnational debt. One step in this direction would permit leading cities to issue municipal bonds based on objective financial standards.Banks&Banking Reform,Urban Economics,Public&Municipal Finance,Municipal Financial Management,Intergovernmental Fiscal Relations and Local Finance Management
The Contribution of Social Networks to Income Inequality in Rural China: A Regression-Based Decomposition and Cross-Regional Comparison
This study aims to quantify the contribution of social networks, i.e., guanxi,to income inequality in rural households in China. One purpose is to understand how this influence varies across regions with different levels of marketization and economic development. Employing household survey data in rural China, we find that social networks contribute 12.1%-13.4% to income inequality among households in rural China, ranking fourth after village identifiers, nonfarm employment, and education. We also find that social networks exert a greater impact on income and a greater contribution to income inequality in Eastern China, compared with Middle-Western China where economic development is relatively slower. Our findings challenge the conventional understanding that social capital is the capital of the poor. In other words,the rich get richer in richer regions through social networks.Social Network, Income Inequality, Marketization, Regression-Based Decomposition
Pion Production in Heavy-ion Collisions in the 1 A GeV region
Within the framework of the improved isospin dependent quantum molecular
dynamics (ImIQMD) model, the pion emission in heavy-ion collisions in the
region 1 A GeV is investigated systematically, in which the pion is considered
to be mainly produced by the decay of resonances (1232) and
N*(1440). The in-medium dependence and Coulomb effects of the pion production
are included in the calculation. Total pion multiplicity and
yields are calculated for the reaction Au+Au in central
collisions for selected Skyrme parameters SkP, SLy6, Ska, SIII and compared
them with the measured data by the FOPI collaboration.Comment: 9 pages, 5 figure
Necessity for quantum coherence of nondegeneracy in energy flow
In this work, we show that the quantum coherence among non-degenerate energy
subspaces (CANES) is essential for the energy flow in any quantum system. CANES
satisfies almost all of the requirements as a coherence measure, except that
the coherence within degenerate subspaces is explicitly eliminated.We show that
the energy of a system becomes frozen if and only if the corresponding CANES
vanishes, which is true regardless of the form of interaction with the
environment. However, CANES can remain zero even if the entanglement changes
over time. Furthermore, we show how the power of energy flow is bounded by the
value of CANES. An explicit relation connecting the variation of energy and
CANES is also presented. These results allow us to bound the generation of
system-environment correlation through the local measurement of the system's
energy flow
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