# Topological entanglement entropy only defined for a system in the ground state?

What happens to the topological entanglement entropy of a system, when it is driven out of its groundstate by increasing the temperature?

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This question may be answered in general, but it always helps if one starts with simple concrete models. A good starting point is this paper. –  Isidore Seville Jan 6 '14 at 2:09
Here is a free version of the paper linked above (arxiv.org/abs/0704.3616) –  Joel Klassen Jan 12 '14 at 6:08