def neg_mct_gate(lneg):
neg_mct = AncillaCircuit(3)
for i in lneg:
neg_mct.x(i)
neg_mct.ccx(0, 1, 2)
for i in lneg:
neg_mct.x(i)
return neg_mct.to_ancilla_gate(True)
def makeIntegerComparator(num_state_qubits, value, geq=True, with_uncomp=True):
"""Build the comparator circuit."""
or_gate = OR(2).to_gate()
qr_state = QuantumRegister(num_state_qubits, name='state')
q_compare = QuantumRegister(1, name='compare')
circuit = AncillaCircuit(qr_state, q_compare)
circuit.addQfreeGate(or_gate)
qr_ancilla = circuit.new_ancilla_register(
num_state_qubits - 1, name='ancilla') if num_state_qubits > 1 else None
if value <= 0: # condition always satisfied for non-positive values
if geq: # otherwise the condition is never satisfied
circuit.x(q_compare)
# condition never satisfied for values larger than or equal to 2^n
elif value < pow(2, num_state_qubits):
if num_state_qubits > 1:
twos = _get_twos_complement(num_state_qubits, value)
for i in range(num_state_qubits):
if i == 0:
if twos[i] == 1:
circuit.cx(qr_state[i], qr_ancilla[i])
elif i < num_state_qubits - 1:
if twos[i] == 1:
circuit.append(
or_gate,
[qr_state[i], qr_ancilla[i - 1], qr_ancilla[i]])
else:
circuit.ccx(qr_state[i], qr_ancilla[i - 1],
qr_ancilla[i])
else:
if twos[i] == 1:
circuit.append(
or_gate,
[qr_state[i], qr_ancilla[i - 1], q_compare])
else:
circuit.ccx(qr_state[i], qr_ancilla[i - 1], q_compare)
# flip result bit if geq flag is false
if not geq:
circuit.x(q_compare)
else:
# num_state_qubits == 1 and value == 1:
circuit.cx(qr_state[0], q_compare)
# flip result bit if geq flag is false
if not geq:
circuit.x(q_compare)
else:
if not geq: # otherwise the condition is never satisfied
circuit.x(q_compare)
return circuit
def makesOracle(i, n):
# Creates the oracle finding exactly i on n qubits (+ 1 for target)(or its lowest n bits if i >= 2^n)
# Could use some uncomputation...
ctrls = QuantumRegister(n)
target = QuantumRegister(1)
fcirc = AncillaCircuit(ctrls,
target,
name="oracle_" + str(i) + "_" + str(n))
format_str = '{0:0' + str(n) + 'b}'
binary_i = format_str.format(i)[::-1]
for j in range(n):
if binary_i[j] == '0':
fcirc.x(ctrls[j])
fcirc.mcx(ctrls[:], target[0])
for j in range(n):
if binary_i[j] == '0':
fcirc.x(ctrls[j])
return fcirc.to_ancilla_gate()
def makesDJ(num_qubits, oracle_gate=None):
#Builds the Deutsch Jozsa circuit for n + 1 qubits, finding the value 111...111
var_reg = QuantumRegister(num_qubits, name='vals')
out_reg = QuantumRegister(1, name='out')
circ = AncillaCircuit(var_reg, out_reg)
circ.h(var_reg)
circ.x(out_reg)
circ.h(out_reg)
if oracle_gate:
circ.append(oracle_gate, [*var_reg, out_reg[0]])
else:
circ.mcx(var_reg, out_reg)
circ.h(var_reg)
return (circ, var_reg)
def makesGroverCircuit(n, oracle=None, nb_sols=1):
# grover circuit on n qubits, without measurements as uncomp cannot deal with that yet
nbIter = int(np.floor(np.pi / 4.0 * np.sqrt(pow(2, n))))
working_qubits = QuantumRegister(n, name='r')
phase_qubit = QuantumRegister(1, name='p')
circ = AncillaCircuit(working_qubits, phase_qubit)
circ.x(phase_qubit[0])
circ.h(phase_qubit[0])
circ.h(working_qubits)
for l in range(nbIter):
if oracle:
circ.append(oracle, [*working_qubits[:], phase_qubit[0]])
else:
circ.mcx(working_qubits, phase_qubit)
#Grover diffusion operator
circ.h(working_qubits)
circ.x(working_qubits)
circ.h(working_qubits[-1])
circ.mcx(working_qubits[:-1], working_qubits[-1])
circ.h(working_qubits[-1])
circ.x(working_qubits)
circ.h(working_qubits)
# bring the phase qubit back to 0, we can't uncompute it, as it went through cz, non qfree -> no need to uncomp it, Qiskit doesn't
#circ.h(phase_qubit[0])
#circ.x(phase_qubit)
return (circ, working_qubits)
def makesAdder(num_qubits):
#[a, b, s]: s = a + b, a and b made of num_qubits each
# returns an AncillaCircuit, without uncomputation
def neg_mct_gate(lneg):
neg_mct = AncillaCircuit(3)
for i in lneg:
neg_mct.x(i)
neg_mct.ccx(0, 1, 2)
for i in lneg:
neg_mct.x(i)
return neg_mct.to_ancilla_gate(True)
a = QuantumRegister(num_qubits, name="a")
b = QuantumRegister(num_qubits, name="b")
s = QuantumRegister(num_qubits, name="s")
c = AncillaRegister(num_qubits, name="c")
circuit = AncillaCircuit(a, b, s, c)
for i in range(num_qubits - 1):
#sum
t = circuit.new_ancilla_register(1, name='t' + str(i))
circuit.cx(a[i], t)
circuit.cx(b[i], t) #to be quipper like
circuit.cx(t, s[i])
circuit.cx(c[i], s[i])
#carry
v = circuit.new_ancilla_register(1, name='v' + str(i))
circuit.append(neg_mct_gate([0, 1]), [a[i], b[i], v])
circuit.append(neg_mct_gate([1]), [v, c[i], c[i + 1]])
circuit.x(c[i + 1])
circuit.cx(a[num_qubits - 1], s[num_qubits - 1])
circuit.cx(b[num_qubits - 1], s[num_qubits - 1])
circuit.cx(c[num_qubits - 1], s[num_qubits - 1])
return circuit