Mana in Haar-random states
arXiv:2011.13937
Abstract
Mana is a measure of the amount of non-Clifford resources required to create a state; the mana of a mixed state on qudits bounded by ; the state's second Renyi entropy. We compute the mana of Haar-random pure and mixed states and find that the mana is nearly logarithmic in Hilbert space dimension: that is, extensive in number of qudits and logarithmic in qudit dimension. In particular, the average mana of states with less-than-maximal entropy falls short of that maximum by . We then connect this result to recent work on near-Clifford approximate -designs; in doing so we point out that mana is a useful measure of non-Clifford resources precisely because it is not differentiable.