Degree of entanglement in a quantum measurement process

Abstract

We suggest a quantum measurement model in an ion trap which specifies the probability distribution of two, distinct internal ground states of a trapped four-level ion. The external degrees of motion of the four-level ion constitute the meter which, in turn, is coupled to the environment by engineered reservoirs. In a previous publication, a similar measurement model was employed to test decoherence effects on quantum nonlocality in phase space on the basis of coincidence measurements of the entangled system-meter scheme. Here, we study the effects of decoherence on the entanglement of formation characterized by the concurrence. The concurrence of the system enables to find the maximum possible violation of the Bell inequality. Surprisingly, this model gives illustrative insights into the question to what extend the Bell inequality can be considered as a measure of entanglement.

Revtex, 8 pages, 5 eps figures

References in corpus (2)

• Degree of entanglement for two qubits
• Mixedness in Bell-violation vs. Entanglement of Formation

Cited by in corpus (5)

• Two-qubit mixed states more entangled than pure states: Comparison of the relative entropy of entanglement for a given nonlocality
• Violation of Bell inequality and entanglement of decaying Werner states
• Entangling quantum measurement and its properties
• Quantification of Quantum Entanglement in a Multiparticle System of Two-Level Atoms Interacting with a Squeezed Vacuum State of the Radiation Field
• A total measure of multi-particle quantum correlations in atomic Schrödinger cat states