Detection of Macroscopic Entanglement by Correlation of Local Observables

Abstract

We propose a correlation of local observables on many sites in macroscopic quantum systems. By measuring the correlation one can detect, if any, superposition of macroscopically distinct states, which we call macroscopic entanglement, in arbitrary quantum states that are (effectively) homogeneous. Using this property, we also propose an index of macroscopic entanglement.

Although the index q was proposed for mixed states, it is also applicable to pure states, on which we fix minor bugs (that will be reported in PRL as erratum). The conclusions of the paper remain unchanged. (4 pages, no figures.)

References in corpus (3)

• Macroscopic entanglement of many-magnon states
• Correlations of observables in chaotic states of macroscopic quantum systems
• Appearance and Stability of Anomalously Fluctuating States in Shor's Factoring Algorithm

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