Multipartite Entanglement Accumulation in Quantum States: Localizable Generalized Geometric Measure

TL;DR

This paper introduces a new measure of multipartite entanglement based on local measurements and demonstrates its ability to surpass original entanglement levels, signaling quantum critical phenomena in spin models.

Contribution

It defines a localizable generalized geometric measure and shows its effectiveness in quantifying and enhancing multipartite entanglement in quantum states.

Findings

Localized entanglement can exceed original entanglement levels.

Multiple-party measurements can enhance localizable entanglement.

The measure signals quantum criticality even with finite-size effects.

Abstract

Multiparty quantum states are useful for a variety of quantum information and computation protocols. We define a multiparty entanglement measure based on local measurements on a multiparty quantum state, and an entanglement measure averaged on the post-measurement ensemble. Using the generalized geometric measure as the measure of multipartite entanglement for the ensemble, we demonstrate, in the case of several well-known classes of multipartite pure states, that the localized multipartite entanglement can exceed the entanglement present in the original state. We also show that measurement over multiple parties may be beneficial in enhancing localizable multipartite entanglement. We point out that localizable generalized geometric measure faithfully signals quantum critical phenomena in well-known quantum spin models even when considerable finite-size effect is present in the system.