test_qft.py 文件源码

def test_quantum_fourier():
    assert QFT(0, 3).decompose() == \
        SwapGate(0, 2)*HadamardGate(0)*CGate((0,), PhaseGate(1)) * \
        HadamardGate(1)*CGate((0,), TGate(2))*CGate((1,), PhaseGate(2)) * \
        HadamardGate(2)

    assert IQFT(0, 3).decompose() == \
        HadamardGate(2)*CGate((1,), RkGate(2, -2))*CGate((0,), RkGate(2, -3)) * \
        HadamardGate(1)*CGate((0,), RkGate(1, -2))*HadamardGate(0)*SwapGate(0, 2)

    assert represent(QFT(0, 3), nqubits=3) == \
        Matrix([[exp(2*pi*I/8)**(i*j % 8)/sqrt(8) for i in range(8)] for j in range(8)])

    assert QFT(0, 4).decompose()  # non-trivial decomposition
    assert qapply(QFT(0, 3).decompose()*Qubit(0, 0, 0)).expand() == qapply(
        HadamardGate(0)*HadamardGate(1)*HadamardGate(2)*Qubit(0, 0, 0)
    ).expand()