Multi control bloq via single control bloq and And ladder

from qualtran import Bloq, CompositeBloq, BloqBuilder, Signature, Register
from qualtran import QBit, QInt, QUInt, QAny
from qualtran.drawing import show_bloq, show_call_graph, show_counts_sigma
from typing import *
import numpy as np
import sympy
import cirq

ControlledViaAnd

Reduces a generic controlled bloq to a singly-controlled bloq using an And ladder.

Implements a generic controlled version of the subbloq, by first reducing the arbitrary control to a single qubit, and then using a single-qubit-controlled variant of the subbloq.

For signature, see :class:Controlled.

Parameters

• subbloq: The bloq we are controlling.

• ctrl_spec: The specification for how to control the bloq.

from qualtran.bloqs.mcmt import ControlledViaAnd

Example Instances

from qualtran import CtrlSpec, QInt, QUInt
from qualtran.bloqs.basic_gates import Hadamard

controlled_via_and_ints = ControlledViaAnd(
    Hadamard(),
    CtrlSpec(
        qdtypes=(QUInt(4), QInt(4)), cvs=(np.array([0, 1, 2, 3]), np.array([0, 1, -1, -2]))
    ),
)

from qualtran.bloqs.basic_gates import Hadamard

controlled_via_and_qbits = ControlledViaAnd(Hadamard(), CtrlSpec(cvs=(np.array([0, 1, 1, 0]),)))

Graphical Signature

from qualtran.drawing import show_bloqs
show_bloqs([controlled_via_and_ints, controlled_via_and_qbits],
           ['`controlled_via_and_ints`', '`controlled_via_and_qbits`'])

Call Graph

from qualtran.resource_counting.generalizers import ignore_split_join
controlled_via_and_ints_g, controlled_via_and_ints_sigma = controlled_via_and_ints.call_graph(max_depth=1, generalizer=ignore_split_join)
show_call_graph(controlled_via_and_ints_g)
show_counts_sigma(controlled_via_and_ints_sigma)

Counts totals:

• CHadamard: 1

• CtrlSpecAnd: 1

• CtrlSpecAnd†: 1

Nested Controls

Calling controlled on a ControlledViaAnd returns another ControlledViaAnd by combining the existing and new controls into a single control specification.

nested_ctrl_bloq = controlled_via_and_qbits.controlled(CtrlSpec(cvs=[1, 1]))
show_bloqs([nested_ctrl_bloq])

show_call_graph(nested_ctrl_bloq)