Abstract:
In this work, the ensemble of iterated unitary quantum gates distributed uniformly with respect to the Haar measure on the unitary group is studied. Instead of using random quantum circuits with non-local random unitaries, we look at what happens when there are fixed nonlocal unitaries but haar random locals at intermediate steps. Recently it was shown for a 2 qubit system that such an interlacing of local gates can lead to exponential growth of entanglement in time. Here we try to extend those results to a 4 qubit case.