def mcz_gray(c: Circuit, ctrl: Sequence[int], target: int) -> Circuit:
"""A macro of multi controlled Z gate."""
n_ctrl = len(ctrl)
if n_ctrl == 0:
return c.z[target]
angles = [math.pi / 2**(n_ctrl - 1), -math.pi / 2**(n_ctrl - 1)]
for c0, c1, parity in gen_gray_controls(n_ctrl):
if c0 >= 0:
c.cx[ctrl[c0], ctrl[c1]]
c.cr(angles[parity])[ctrl[c1], target]
return c
def mcr_gray(c: Circuit, theta: float, ctrl: Sequence[int],
target: int) -> Circuit:
"""A macro of multi controlled R gate."""
n_ctrl = len(ctrl)
if n_ctrl == 0:
return c.r(theta)[target]
angles = [theta / 2**(n_ctrl - 1), -theta / 2**(n_ctrl - 1)]
for c0, c1, parity in gen_gray_controls(n_ctrl):
if c0 >= 0:
c.cx[ctrl[c0], ctrl[c1]]
c.cr(angles[parity])[ctrl[c1], target]
return c
def mcu_gray(c: Circuit, theta: float, phi: float, lam: float, gamma: float,
ctrl: Sequence[int], target: int) -> Circuit:
"""A macro of multi controlled U gate."""
n_ctrl = len(ctrl)
if n_ctrl == 0:
return c.u(theta, phi, lam, gamma)[target]
if n_ctrl == 1:
return c.cu(theta, phi, lam, gamma)[ctrl[0], target]
mat = UGate.create(0, (theta, phi, lam, gamma)).matrix()
for _ in range(n_ctrl - 1):
mat = sqrt_2x2_matrix(mat)
params = calc_u_params(mat)
params_dagger = -params[0], -params[2], -params[1], -params[3]
for c0, c1, parity in gen_gray_controls(n_ctrl):
if c0 >= 0:
c.cx[ctrl[c0], ctrl[c1]]
if parity:
c.cu(*params_dagger)[ctrl[c1], target]
else:
c.cu(*params)[ctrl[c1], target]
return c