At qubits, with the gate set used in the counting argument, each gate position has…
PHYSICS · Subjective · Fermi University Physics · Quantum Information & Technology · The quantum circuit model and quantum algorithms · The quantum circuit model and quantum algorithms
Quantum Information and Technology, Ch The quantum circuit model
Problem
At n=20 qubits, with the gate set {H,T,CNOT} used in the counting argument, each gate position has n(n+1) choices (an H or a T on any of the n wires, or a CNOT on any ordered pair of the n wires). Using the same reasoning as the n=10 estimate already worked, estimate the smallest circuit size G such that circuits of size G could possibly reach even one per cent of the states of the 20-qubit sphere to accuracy 0.1.