Is macroscopic entanglement a typical trait of many-particle quantum states?

Abstract

We elucidate the relationship between Schrödinger-cat-like macroscopicity and geometric entanglement, and argue that these quantities are not interchangeable. While both properties are lost due to decoherence, we show that macroscopicity is rare in uniform and in so-called random physical ensembles of pure quantum states, despite possibly large geometric entanglement. In contrast, permutation-symmetric pure states feature rather low geometric entanglement and strong and robust macroscopicity.

13 pages, 9 figures

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Cited by in corpus (8)

• Random bosonic states for robust quantum metrology
• Asymptotic role of entanglement in quantum metrology
• Entanglement in macroscopic systems
• Disturbance-Based Measure of Macroscopic Coherence
• Quantum macroscopicity measure for arbitrary spin systems and its application to quantum phase transitions
• Scaling of macroscopic superpositions close to a quantum phase transition
• Correlations in local measurements and entanglement in many-body systems
• Entanglement of particles versus entanglement of fields: independent quantum resources