Robust and Indestructible Macroscopic Entanglement

Abstract

In this letter we investigate the possibility of observing macroscopic entanglement, considering realistic factors such as decoherence, particle losses, and measurements of limited precision (coarse-grained collective measurements). This forms the foundation for an operational definition of robust macroscopic entanglement. We also propose an even more resilient concept of macroscopic entanglement, allowing the parties to randomly select their portion of the shared system. Through a straightforward example, we demonstrate that achieving this is feasible using a simple class of quantum states. Our result opens a path for generalizing notions of quantum entanglement, such as a genuine multipartite entanglement in the macroscopic domain.