量子糾纏及其度量
摘要：量子糾纏是首先被Einstein-Podolsky-Rosen(EPR)和薛定諤注意到的不同於經典物理最奇特、最不可思議的1種奇妙現象。它是微觀量子系統內各子系統或各自由度之間關聯的反映。在量子資訊中，糾纏態扮演着極爲重要的角色。可以說如果沒有量子糾纏現象，就不會有現在所說的量子資訊。由於糾纏態特殊的物理性質，使量子資訊具有經典資訊所沒有的許多新的特徵，同時糾纏態也爲資訊傳輸和資訊處理提供了新的`物理資源。本文對量子糾纏以及量子糾纏的度量（包含純態和非純態兩種系統）的歷史淵源和基本概念，以及近年來在理論實踐研究方面的重要進展和在量子資訊科學領域的應用前景，做1個系統、綜合的介紹和討論。
關鍵字：量子糾纏；糾纏的度量；EPR佯謬；薛定諤貓
Quantum entanglement and measurement
Abstract: Quantum entanglement, which is first revealed by Einstein-Podolsky-Rosen(EPR) and Schrodinger, is the unique phenomenon of quantum system. It is the most strange and unbelievable phenomenon which is different from classical physics. It reflects the correlation between different subsystems or freedom of degree in the microscopic quantized system. Quantum entanglement is the key role in the realism of quantum information. Due to the particular physical properties of quantum entanglement, there are some new properties which we cannot find in the classical information theory. Quantum entanglement also provides the key resource for quantum communication and quantum information processing. In this paper we review the concept and history of quantum entanglement, the progress in theory and experiment and the measurement of entanglement.
Keywords：Entanglement; Measurement of the entanglement; EPR-Paradox; Schrodingers Cat.
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