Entrelazamiento cuántico espurio con matrices seudopuras extendidas 4 por 4

Abstract

In this paper, we consider one mathematical extension for the concept NMR pseudo-pure matrix in the particular case of $4\times4$ matrices, from non-physical matrices. Examples of entangled density matrices are presented. Those entanglement, identified by the Peres-Horodecki criterion, is spurious because it is not possible to assign these matrices to any physical state of a system of NMR nuclear spins.