Maximal vacuum entanglement principle

Xin-Hua Cai, Le‐Man Kuang

This paper proposes a scheme for teleporting an arbitrary coherent superposition state of two equal-amplitude and opposite-phase squeezed vacuum states (SVS) via a symmetric 50/50 beam splitter and photodetectors. It is shown that the quantum teleportation scheme has the successful probability 1/4. Maximally entangled SVS's are used as quantum channel for realizing the teleportation scheme. It is shown that if an initial quantum channel is in a pure but not maximally entangled SVS, the quantum channel may be distilled to a maximally entangled SVS through entanglement concentration.

Muxin Han, S. Jay Olson, Jonathan P. Dowling

Building on the well-known Unruh-Davies effect, we examine the effects of projective measurements and quantum communications between accelerated and stationary observers. We find that the projective measurement by a uniformly accelerated observer can excite real particles from the vacuum in the inertial frame, even if no additional particles are created by the measurement process in the accelerating frame. Furthermore, we show that the particles created by this accelerating measurement can be highly entangled in the inertial frame, and it is also possible to use this process to generate even maximally entangled two-qubit states by a certain arrangement of measurements. As a by-product of our analysis, we also show that a single qubit of information can be perfectly transmitted from the accelerating observer to the inertial one. In principle, such an effect could be exploited in designing an entangled-state generator for quantum communication.

Alba Cervera-Lierta

MB

C. V. Namitha, K. G. Paulson, S. V. M. Satyanarayana

We investigate the entanglement dynamics of two spatially separated, identical two level atoms interacting via dipole forces and coupled to a common vacuum reservoir. We choose a general class of maximally entangled mixed states (MEMS) as initial states and study the entanglement dynamics. We observe all rank 4 MEMS exhibit entanglement sudden death followed by its revival. The relevance of the rank of the state and its change in the evolution is studied.