https://doi.org/10.1140/epjd/e2014-50387-8
Regular Article
Correlation evolution and monogamy of two geometric quantum discords in multipartite systems
1 College of Physical Science and
Information Engineering and Hebei Advance Thin Films Laboratory, Hebei Normal
University, Shijiazhuang, Hebei
050024, P.R.
China
2 Department of Physics and Center of
Theoretical and Computational Physics, The University of Hong Kong,
Pokfulam Road, Hong Kong, P.R.
China
a
e-mail: ykbai@semi.ac.cn
b
e-mail: zwang@hku.hk
Received:
15
May
2014
Received in final form:
6
July
2014
Published online:
1
October
2014
We explore two different geometric quantum discords defined respectively via the trace norm (GQD-1) and Hilbert-Schmidt norm (GQD-2) in multipartite systems. A rigorous hierarchy relation is revealed for the two GQDs in a class of symmetric two-qubit X-shape states. For multiqubit pure states, it is found that both GQDs are related to the entanglement concurrence, with the hierarchy relation being saturated. Furthermore, we look into a four-partite dynamical system consisting of two cavities interacting with independent reservoirs. It is found that the GQD-2 can exhibit various sudden change behaviours, while the GQD-1 only evolves asymptotically, with the two GQDs exhibiting different monogamous properties.
Key words: Quantum Information
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2014