Open AccessPairwise correlations via quantum discord and its geometric measure in a four-qubit spin chain
Author(s) -
AbdelBaset A. Mohamed
Publication year - 2013
Publication title -
journal of the egyptian mathematical society
Language(s) - English
Resource type - Journals
eISSN - 2090-9128
pISSN - 1110-256X
DOI - 10.1016/j.joems.2012.10.005
Subject(s) - quantum discord , qubit , quantum entanglement , pairwise comparison , measure (data warehouse) , quantum correlation , mathematics , quantum mechanics , spin (aerodynamics) , statistical physics , quantum , physics , statistics , computer science , database , thermodynamics
The dynamic of pairwise correlations, including quantum entanglement (QE) and discord (QD) with geometric measure of quantum discord (GMQD), are shown in the four-qubit Heisenberg XX spin chain. The results show that the effect of the entanglement degree of the initial state on the pairwise correlations is stronger for alternate qubits than it is for nearest-neighbor qubits. This parameter results in sudden death for QE, but it cannot do so for QD and GMQD. With different values for this entanglement parameter of the initial state, QD and GMQD differ and are sensitive for any change in this parameter. It is found that GMQD is more robust than both QD and QE to describe correlations with nonzero values, which offers a valuable resource for quantum computation