Robust Quantum Random Access Memory

A "bucket brigade" architecture for a quantum random memory of N = 2(n) memory cells needs n(n + 5)/2 times of quantum manipulation on control circuit nodes per memory call. Here we propose a scheme in which only on average n/2 times manipulations are required to accomplish a memory call. This scheme may significantly decrease the time spent on a memory call and the average overall error rate per memory call. A physical implementation scheme is discussed for storing an arbitrary state in a selected memory cell followed by reading it out.