Stable macroscopic quantum superpositions

Abstract

We study the stability of superpositions of macroscopically distinct quantum states under decoherence. We introduce a class of quantum states with entanglement features similar to Greenberger-Horne-Zeilinger (GHZ) states, but with an inherent stability against noise and decoherence. We show that in contrast to GHZ states, these so-called concatenated GHZ states remain multipartite entangled even for macroscopic numbers of particles and can be used for quantum metrology in noisy environments. We also propose a scalable experimental realization of these states using existing ion-trap set-ups.

4 pages, 1 figure; v2: minor changes due to referee reports

References in corpus (4)

• Scaling laws for the decay of multiqubit entanglement
• Schroedinger Cat: Entanglement test in a Micro-Macroscopic system
• Optimal control of entangling operations for trapped ion quantum computing
• Scalability of GHZ and random-state entanglement in the presence of decoherence