Local uncertainty relations serving as measures of entanglement in a bipartite two-level system

Abstract

We comment on the recent suggestion to use a family of local uncertainty relations as a standard way of quantifying entanglement in two-qubit systems. Some statements made on the applicability of the proposed "measures" are overly optimistic. We exemplify how these specific "measures" fall short, and present a minor modification of the general theory which uses the same experimentally gathered information, but in a slightly different, better way.

5 pages, 1 figure

References in corpus (4)

• Witnessing multipartite entanglement
• Violation of local uncertainty relations as a signature of entanglement
• Experimental Detection of Entanglement with Polarized Photons
• Inclusion relations among separability criteria

Cited by in corpus (4)

• Lower bounds on concurrence and separability conditions
• Entanglement criteria based on local uncertainty relations are strictly stronger than the computable cross norm criterion
• Entanglement quantification through local observable correlations
• Experimental entanglement verification and quantification via uncertainty relations