We study an analog of the well-known Gel’fand Pinsker Channel which uses quantum states for the transmission of the data. We consider the case where both the sender’s inputs to the channel and the channel states are to be taken from a finite set (cq-channel with state information at the sender). We distinguish between causal and non-causal channel state information at the sender. The receiver r...

Entanglement of purification was introduced by Terhal et al.[6] for characterizing the bound of the generation of correlated states from maximally entangled states with sublinear size of classical communication. On the other hand, M. Horodecki [5] obtained the optimal compression rate with a mixed states ensemble in the visible setting. In this paper, we prove that the optimal visible compressi...

We show that although we can not distill a singlet from many pairs of bound entangled states, the concurrence and tangle of two entangled quantum states are always strictly larger than that of one, even both entangled quantum states are bound entangled. We present a relation between the concurrence and the fidelity of optimal teleportation. We also give new upper and lower bounds for concurrenc...

We discuss the canonical form for a pure state of three identical bosons in two modes, and classify its entanglement correlation into two types, the analogous GHZ and the W types as well known in a system of three distinguishable qubits. We have performed a detailed study of two important entanglement measures for such a system, the concurrence C and the triple entanglement measure τ . We have ...

In this paper we study the time evolution of (Rényi) entanglement entropies for locally excited states in four dimensional free massless fermionic field theory. Locally excited states are defined by being acted by various local operators on the ground state. Their excesses are defined by subtracting (Rényi) entanglement entropy for the ground state from those for locally excited states. They fi...

quantum state diffusion, measurement Quantum state diffusion is a theory which has applications to both the foundations of quantum theory and to the behaviour of open quantum systems, quantum systems interacting with environments. This article is an extended essay review of Quantum State Diffusion  the first book [1] on the theory, written by one of its originators, Ian Percival.

A new notation for the quantum teleportation of finite dimensional quantum state through a generally entangled quantum channel is introduced. For a given quantum channel an explict mathematical criterion that governs the faithful teleportation is presented. 1 [email protected] Quantum teleportation has been introduced by Benett et al. [1] and discussed by a number of authors for two d...

The modern development of quantum technology enables people to control quantum process of microscopic system by external field [1, 2, 3, 4, 5, 6]. In the point of view of quantum mechanics, the objective of a quantum control is to reach a desired state (called target state) from an initial state of the controlled system by manipulating its external parameters. Some aspects in quantum informatio...

In its most general form, the atom chip is a device in which neutral or charged particles are positioned in an isolating environment such as vacuum (or even a carbon solid state lattice) near the chip surface. The chip may then be used to interact in a highly controlled manner with the quantum state. I outline the importance of material science to quantum computing (QC) with atom chips, where t...