Mixed State Entanglement: Manipulating Polarisation- Entangled Photons

Thew, R.T. ; Munro, W.J.

HP Development Company

关键词: characterisation of entanglement;    entanglement manipulation;    mixed states;   

RP-ID  :  HPL-2001-70

学科分类：计算机科学（综合）

美国|英语

来源: HP Labs

【 摘 要 】

There has been much discussion recently regarding entanglement transformations in terms of local filtering operations and whether the optimal entanglement for an arbitrary two-qubit state could be realised. We introduce an experimentally realisable scheme for manipulating the entanglement of an arbitrary state of two polarisation entangled qubits. This scheme is then used to provide some perspective to the mathematical concepts inherent in this field with respect to a laboratory environment. Specifically, we look at how to extract enhanced entanglement from systems with a fixed rank and in the case where the rank of the density operator for the state can be reduced, show how the state can be made arbitrarily close to a maximally entangled pure state. In this context we also discuss bounds on entanglement in mixed states. Notes: R.T. Thew, Special Research Centre for Quantum Computer Technology, University of Queensland, Brisbane, Australia 12 Pages