def main():
# parameters for generating random state: |psi>
alpha, beta, gamma = random.random(), random.random(), random.random()
# reference state: T|psi>
qs_expect = QState(1)
qs_expect.rz(0, phase=alpha).rx(0, phase=beta).rz(0, phase=gamma).t(0)
# prepare initial state
qs = QState(3)
qs.h(0).s(0) # |Y>
qs.h(1).t(1) # |A>
qs.rz(2, phase=alpha).rx(2, phase=beta).rz(2, phase=gamma) # |psi>
# T gate (only with X,Z,H,CNOT and measurement)
qs.cx(1, 2)
mval = qs.m(qid=[2]).last
if mval == '1':
qs.cx(1, 0).h(0).cx(1, 0).h(0)
qs.x(1).z(1)
qs_actual = qs.partial(qid=[1])
# show the result
print("== expect ==")
qs_expect.show()
print("== actual ==")
qs_actual.show()
print("== fidelity ==")
print("{:.6f}".format(qs_actual.fidelity(qs_expect)))
def main():
a = random.uniform(0.0, 1.0)
b = random.uniform(0.0, 1.0)
phi = random.uniform(0.0, 1.0)
print("a,b = {0:.4f}, {1:.4f}".format(a,b))
print("phi = {0:.4f}".format(phi))
print("** one-way quantum computing")
# graph state
qs_oneway = QState(2)
qs_oneway.ry(0, phase=a).rz(0, phase=b) # input state (random)
qs_oneway.h(1)
qs_oneway.cz(0,1)
# measurement
s = qs_oneway.m([0], shots=1, angle=0.5, phase=phi)
# result state
qs_oneway.show([1])
print("** conventianal quantum gate")
qs_gate = QState(1)
qs_gate.ry(0, phase=a).rz(0, phase=b) # input state (random)
qs_gate.rz(0, phase=-phi).h(0)
qs_gate.show()
def main():
print("== hadamard gate ==")
print("** one-way quantum computing")
# graph state
qs_oneway = QState(5)
qs_oneway.h(1).h(2).h(3).h(4)
qs_oneway.cz(0, 1).cz(1, 2).cz(2, 3).cz(3, 4)
# measurement
qs_oneway.mx([0], shots=1)
qs_oneway.my([1], shots=1)
qs_oneway.my([2], shots=1)
qs_oneway.my([3], shots=1)
# result state
qs_oneway.show([4])
print("** conventianal quantum gate")
qs_gate = QState(1)
qs_gate.h(0)
qs_gate.show()
def main():
print("== general rotation ==")
alpha = random.uniform(0.0, 1.0)
beta = random.uniform(0.0, 1.0)
gamma = random.uniform(0.0, 1.0)
print("(euler angle = {0:.4f}, {1:.4f}, {2:.4f})".format(
alpha, beta, gamma))
print("** one-way quantum computing")
# graph state
qs_oneway = QState(5)
qs_oneway.h(1).h(2).h(3).h(4)
qs_oneway.cz(0, 1).cz(1, 2).cz(2, 3).cz(3, 4)
# measurement
alpha_oneway = alpha
beta_oneway = beta
gamma_oneway = gamma
s0 = qs_oneway.m([0], shots=1, angle=0.5, phase=0.0).lst
if s0 == 1:
alpha_oneway = -alpha_oneway
s1 = qs_oneway.m([1], shots=1, angle=0.5, phase=alpha_oneway).lst
if s1 == 1:
beta_oneway = -beta_oneway
s2 = qs_oneway.m([2], shots=1, angle=0.5, phase=beta_oneway).lst
if (s0 + s2) % 2 == 1:
gamma_oneway = -gamma_oneway
s3 = qs_oneway.m([3], shots=1, angle=0.5, phase=gamma_oneway).lst
# result state
qs_oneway.show([4])
print("** conventianal quantum gate")
qs_gate = QState(1)
qs_gate.rx(0, phase=alpha).rz(0, phase=beta).rx(0, phase=gamma)
qs_gate.show()
def main():
print("== CNOT gate ==")
print("** one-way quantum computing")
# graph state
qs_oneway = QState(15)
qs_oneway.h(0)
qs_oneway.h(1).h(2).h(3).h(4).h(5).h(6).h(7)
qs_oneway.h(9).h(10).h(11).h(12).h(13).h(14)
qs_oneway.cz(0, 1).cz(1, 2).cz(2, 3).cz(3, 4).cz(4, 5).cz(5, 6)
qs_oneway.cz(3, 7).cz(7, 11)
qs_oneway.cz(8, 9).cz(9, 10).cz(10, 11).cz(11, 12).cz(12, 13).cz(13, 14)
# measurement
qs_oneway.mx([0], shots=1)
qs_oneway.my([1], shots=1)
qs_oneway.my([2], shots=1)
qs_oneway.my([3], shots=1)
qs_oneway.my([4], shots=1)
qs_oneway.my([5], shots=1)
qs_oneway.my([7], shots=1)
qs_oneway.mx([8], shots=1)
qs_oneway.mx([9], shots=1)
qs_oneway.mx([10], shots=1)
qs_oneway.my([11], shots=1)
qs_oneway.mx([12], shots=1)
qs_oneway.mx([13], shots=1)
qs_oneway.show([6, 14])
print("** conventianal quantum gate")
qs_gate = QState(2)
qs_gate.h(0)
qs_gate.cx(0, 1)
qs_gate.show()
BELL_PHI_PLUS = 0
BELL_PHI_MINUS = 3
BELL_PSI_PLUS = 1
BELL_PSI_MINUS = 2
qs = QState(3)
# prepare qubit (id=0) that Alice want to send to Bob by rotating around X,Z
qs.ry(0,phase=0.3).rz(0,phase=0.4)
# make entangled 2 qubits (id=1 for Alice, id=2 for Bob)
qs.h(1).cx(1,2)
# initial state (before teleportation)
print("== Alice (initial) ==")
qs.show([0])
print("== Bob (initial) ==")
qs.show([2])
# Alice execute Bell-measurement to her qubits 0,1
print("== Bell measurement ==")
result = qs.mb([0,1],shots=1).lst
# Bob operate his qubit (id=2) according to the result
if result == BELL_PHI_PLUS:
print("result: phi+")
elif result == BELL_PSI_PLUS:
print("result: psi+")
qs.x(2)
elif result == BELL_PSI_MINUS:
print("result: psi-")
def faulttolerant_m(qs_in):
anc = [0, 1, 2, 3, 4, 5, 6] # ancila
cod = [7, 8, 9, 10, 11, 12, 13] # steane code
qs_anc = QState(7)
qs_total = qs_anc.tenspro(qs_in)
qs_total.h(anc[0])
[qs_total.cx(anc[0], anc[i]) for i in range(1, 7)]
[qs_total.cz(anc[i], cod[i]) for i in range(7)]
[qs_total.cx(anc[0], anc[i]) for i in range(1, 7)]
qs_total.h(anc[0])
md = qs_total.m(qid=[0], shots=10000)
return md
if __name__ == '__main__':
qs = QState(1).h(0).t(0).h(0) # not fault-tolerant -HTH-
qs.show()
qs_ini = logical_zero() # make initial state (logical zero)
[qs_ini.h(i) for i in range(7)] # operate fault-tolerant H
qs_fin = faulttolerant_t(qs_ini) # operate fault-tlerant T
[qs_fin.h(i) for i in range(7)] # operate fault-tolerant H
md = faulttolerant_m(qs_fin) # execute fault-tolerant measurement
print(md.frequency)
from qlazy import QState, DensOp
qs = QState(4)
qs.h(0).h(1) # unitary operation for 0,1-system
qs.x(2).z(3) # unitary operation for 2,3-system
de1 = DensOp(qstate=[qs], prob=[1.0]) # product state
de1_reduced = de1.patrace([0,1]) # trace-out 0,1-system
print("== partial trace of product state ==")
print(" * trace = ", de1_reduced.trace())
print(" * square trace = ", de1_reduced.sqtrace())
qs.cx(1,3).cx(0,2) # entangle between 0,1-system and 2,3-system
de2 = DensOp(qstate=[qs], prob=[1.0]) # entangled state
de2_reduced = de2.patrace([0,1]) # trace-out 0,1-system
print("== partial trace of entangled state ==")
print(" * trace = ", de2_reduced.trace())
print(" * square trace = ", de2_reduced.sqtrace())
print("== partial state of entangled state ==")
qs.show([2,3])
