Like correlation in probability, there are many more entangled states than disentangled ones.
Their entangled states last 400ns, and the memory holds its value for four times longer.
In particular, they are a convenient way of representing certain types of entangled states.
Short range entangled states are trivial in the sense that they all belong to one phase.
There are several canonical entangled states that appear often in theory and experiments.
The partially entangled states are generally easier to prepare experimentally.
Consequently, there are entangled states which have a positive partial transpose.
So far, we've talked about a single type of entangled state, the singlet state.
What about when we look at entangled states?
So for an entangled state there are more than one entanglement witnesses.