Concurrence in three-qubit system

[Rubens Filho]

Dear all,

I'm studying three-qubit system and i need calculate the concurrente in it. The Qutip have one function to do this in two-qubit system, but for three-qubit system does it have?

[Simon Cross]

Hi Rubens,

The concurrence measures the entanglement of a two-part system, and it
is unclear how to do that without specifying what the two parts of the
system are. In the case of two qubits, it is natural to assume that
the two parts are the two qubits. For three qubits it's unclear what
the two parts are.

One can extend the notion of concurrence to pairs of qudits (e.g. a
pair of qutrits) but qutip does not implement this (although it might
be a nice addition).

Regards,
Simon