1204.6124 (M. Mahdian et al.)

Quantum correlations of Two-Qubit XXZ Heisenberg Chain with
Dzyaloshinsky-Moriya interaction coupled to bath spin as non-Markovian
environment    [PDF]

M. Mahdian, M. Bagherpour Jeddi

We consider the quantum correlations (entanglement and quantum discord) dynamics of two coupled spin qubits with Dzyaloshinsky-Moriya interaction influenced by a locally external magnetic field along $z$-direction and coupled to bath spin-1/2 particles as independent non-Markovian environment. We find that with increasing $D_{z}$ and decreasing $J_{z}$, the value of entanglement and quantum discord increase for both antiferromagnetic and ferromagnetic materials. Not that, this growth is more for the ferromagnetic materials. In addition, we perceive that entanglement and quantum discord decrease with increased temperature and increased coupling constants between reduced system and bath. But, strong quantum correlations within the spins of bath reduce decoherence effects. We discuss about type of the constituent material of the central spins that it can speedup the quantum information processing and as a result, we perceive that one can improve and control the quantum information processing with correct selection of the properties of the reduced system ($J$, $J_{z}$, $D_{z}$).

View original: http://arxiv.org/abs/1204.6124