Otfried Guehne, Universität Siegen
Abstract
In this talk, I present recent results on the characterization
of multiparticle entanglement. First, I will discuss a simple
method which allows to prove that a given state is separable
and not entangled. This has been used to characterize the
decay of entanglement in a recent trapped-ion experiment [1].
Then, I will introduce a method to characterize genuine multipartite
entanglement using a multipartite extension of the criterion of
the positivity of the partial transpose [2]. This criterion
can simply be evaluated using semidefinite programming, even if
the density matrix is not completely known. Combined with the
first method, it results in necessary and sufficient criteria
for genuine multipartite entanglement for important families
of states.
References:
[1] J. T. Barreiro et al., Nature Physics 6, 943 (2010).
[2] B. Jungnitsch et al., Phys. Rev. Lett. 106, 190502 (2011).