877 research outputs found
Exactly Solvable Many-Body Systems and Pseudo-Hermitian Point Interactions
We study Hamiltonian systems with point interactions and give a systematic
description of the corresponding boundary conditions and the spectrum
properties for self-adjoint, PT-symmetric systems and systems with real
spectra. The integrability of one dimensional many body systems with these
kinds of point (contact) interactions are investigated for both bosonic and
fermionic statistics.Comment: 7 page
Measurable bounds for Entanglement of Formation
We study the entanglement of formation for arbitrary dimensional bipartite
mixed unknown states. Experimentally measurable lower and upper bounds for
entanglement of formation are derived.Comment: 9 pages, 4 figure
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
A Remark on the Optimal Cloning of An N-Level Quantum System
We study quantum cloning machines (QCM) that act on an unknown N-level
quantum state and make M copies. We give a formula for the maximum of the
fidelity of cloning and exhibit the unitary transformations that realize this
optimal fidelity. We also extend the results to treat the case of M copies from
() identical N-level quantum systems.Comment: 8 pages, Late
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