Duality relation between coherence and path information in the presence of quantum memory

The wave-particle duality demonstrates a competition relation between wave and particle behavior for a particle going through an interferometer. This duality can be formulated as an inequality, which upper bounds the sum of interference visibility and path information. However, if the particle is entangled with a quantum memory, then the bound may decrease. Here, we find the duality relation between coherence and path information for a particle going through a multipath interferometer in the presence of a quantum memory, offering an upper bound on the duality relation which is directly connected with the amount of entanglement between the particle and the quantum memory.Comment: 6 pages, 1 figure, comments are welcom

Two-copy Quantum Teleportation

We investigate two-copy scenario of quantum teleportation based on Bell measurements. The detailed protocol is presented and the general expression of the corresponding optimal teleportation delity is derived, which is given by the two-copy fully entangled fraction that is invariant under local unitary transformations. We prove that under a speci c case of the protocol, which is signi cant for improving the optimal delity, the set of states with their two-copy fully entangled fractions bounded by a threshold value that required for useful two-copy teleportation is convex and compact. Hence the witness operators exist to separate states that are useful for two-copy teleportation from the rest ones. Moreover, we show that the optimal delity of two-copy teleportation surpasses that of the original one copy teleportation.Comment: 8 pages, 2 figure

Bis[2,6-bis­(4,5-dihydro-1H-imidazol-2-yl)pyridine]manganese(II) bis­(per­chlorate) acetonitrile solvate

In the cation of the title compound, [Mn(C11H13N5)2](ClO4)2·CH3CN, the metal atom is located on a twofold rotation axis and is six-coordinated by six N atoms from two different 2,6-bis­(4,5-dihydro-1H-imidazol-2-yl)pyridine (bip) ligands in a distorted octahedral geometry. The O atoms of the perchlorate anions are disordered with occupancies in the ratio 0.593 (10):0.407 (10). In the crystal, mol­ecules are stabilized by two N—H⋯O hydrogen bonds, forming zigzag chains along the a axis, which are further inter­connected by N—H⋯O hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.50 (1) Å] into a three-dimensional network