ai-content-maker/.venv/Lib/site-packages/sympy/physics/quantum/tests/test_qubit.py

256 lines
8.7 KiB
Python

import random
from sympy.core.numbers import (Integer, Rational)
from sympy.core.singleton import S
from sympy.core.symbol import symbols
from sympy.functions.elementary.miscellaneous import sqrt
from sympy.matrices.dense import Matrix
from sympy.physics.quantum.qubit import (measure_all, measure_partial,
matrix_to_qubit, matrix_to_density,
qubit_to_matrix, IntQubit,
IntQubitBra, QubitBra)
from sympy.physics.quantum.gate import (HadamardGate, CNOT, XGate, YGate,
ZGate, PhaseGate)
from sympy.physics.quantum.qapply import qapply
from sympy.physics.quantum.represent import represent
from sympy.physics.quantum.shor import Qubit
from sympy.testing.pytest import raises
from sympy.physics.quantum.density import Density
from sympy.physics.quantum.trace import Tr
x, y = symbols('x,y')
epsilon = .000001
def test_Qubit():
array = [0, 0, 1, 1, 0]
qb = Qubit('00110')
assert qb.flip(0) == Qubit('00111')
assert qb.flip(1) == Qubit('00100')
assert qb.flip(4) == Qubit('10110')
assert qb.qubit_values == (0, 0, 1, 1, 0)
assert qb.dimension == 5
for i in range(5):
assert qb[i] == array[4 - i]
assert len(qb) == 5
qb = Qubit('110')
def test_QubitBra():
qb = Qubit(0)
qb_bra = QubitBra(0)
assert qb.dual_class() == QubitBra
assert qb_bra.dual_class() == Qubit
qb = Qubit(1, 1, 0)
qb_bra = QubitBra(1, 1, 0)
assert represent(qb, nqubits=3).H == represent(qb_bra, nqubits=3)
qb = Qubit(0, 1)
qb_bra = QubitBra(1,0)
assert qb._eval_innerproduct_QubitBra(qb_bra) == Integer(0)
qb_bra = QubitBra(0, 1)
assert qb._eval_innerproduct_QubitBra(qb_bra) == Integer(1)
def test_IntQubit():
# issue 9136
iqb = IntQubit(0, nqubits=1)
assert qubit_to_matrix(Qubit('0')) == qubit_to_matrix(iqb)
qb = Qubit('1010')
assert qubit_to_matrix(IntQubit(qb)) == qubit_to_matrix(qb)
iqb = IntQubit(1, nqubits=1)
assert qubit_to_matrix(Qubit('1')) == qubit_to_matrix(iqb)
assert qubit_to_matrix(IntQubit(1)) == qubit_to_matrix(iqb)
iqb = IntQubit(7, nqubits=4)
assert qubit_to_matrix(Qubit('0111')) == qubit_to_matrix(iqb)
assert qubit_to_matrix(IntQubit(7, 4)) == qubit_to_matrix(iqb)
iqb = IntQubit(8)
assert iqb.as_int() == 8
assert iqb.qubit_values == (1, 0, 0, 0)
iqb = IntQubit(7, 4)
assert iqb.qubit_values == (0, 1, 1, 1)
assert IntQubit(3) == IntQubit(3, 2)
#test Dual Classes
iqb = IntQubit(3)
iqb_bra = IntQubitBra(3)
assert iqb.dual_class() == IntQubitBra
assert iqb_bra.dual_class() == IntQubit
iqb = IntQubit(5)
iqb_bra = IntQubitBra(5)
assert iqb._eval_innerproduct_IntQubitBra(iqb_bra) == Integer(1)
iqb = IntQubit(4)
iqb_bra = IntQubitBra(5)
assert iqb._eval_innerproduct_IntQubitBra(iqb_bra) == Integer(0)
raises(ValueError, lambda: IntQubit(4, 1))
raises(ValueError, lambda: IntQubit('5'))
raises(ValueError, lambda: IntQubit(5, '5'))
raises(ValueError, lambda: IntQubit(5, nqubits='5'))
raises(TypeError, lambda: IntQubit(5, bad_arg=True))
def test_superposition_of_states():
state = 1/sqrt(2)*Qubit('01') + 1/sqrt(2)*Qubit('10')
state_gate = CNOT(0, 1)*HadamardGate(0)*state
state_expanded = Qubit('01')/2 + Qubit('00')/2 - Qubit('11')/2 + Qubit('10')/2
assert qapply(state_gate).expand() == state_expanded
assert matrix_to_qubit(represent(state_gate, nqubits=2)) == state_expanded
#test apply methods
def test_apply_represent_equality():
gates = [HadamardGate(int(3*random.random())),
XGate(int(3*random.random())), ZGate(int(3*random.random())),
YGate(int(3*random.random())), ZGate(int(3*random.random())),
PhaseGate(int(3*random.random()))]
circuit = Qubit(int(random.random()*2), int(random.random()*2),
int(random.random()*2), int(random.random()*2), int(random.random()*2),
int(random.random()*2))
for i in range(int(random.random()*6)):
circuit = gates[int(random.random()*6)]*circuit
mat = represent(circuit, nqubits=6)
states = qapply(circuit)
state_rep = matrix_to_qubit(mat)
states = states.expand()
state_rep = state_rep.expand()
assert state_rep == states
def test_matrix_to_qubits():
qb = Qubit(0, 0, 0, 0)
mat = Matrix([1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
assert matrix_to_qubit(mat) == qb
assert qubit_to_matrix(qb) == mat
state = 2*sqrt(2)*(Qubit(0, 0, 0) + Qubit(0, 0, 1) + Qubit(0, 1, 0) +
Qubit(0, 1, 1) + Qubit(1, 0, 0) + Qubit(1, 0, 1) +
Qubit(1, 1, 0) + Qubit(1, 1, 1))
ones = sqrt(2)*2*Matrix([1, 1, 1, 1, 1, 1, 1, 1])
assert matrix_to_qubit(ones) == state.expand()
assert qubit_to_matrix(state) == ones
def test_measure_normalize():
a, b = symbols('a b')
state = a*Qubit('110') + b*Qubit('111')
assert measure_partial(state, (0,), normalize=False) == \
[(a*Qubit('110'), a*a.conjugate()), (b*Qubit('111'), b*b.conjugate())]
assert measure_all(state, normalize=False) == \
[(Qubit('110'), a*a.conjugate()), (Qubit('111'), b*b.conjugate())]
def test_measure_partial():
#Basic test of collapse of entangled two qubits (Bell States)
state = Qubit('01') + Qubit('10')
assert measure_partial(state, (0,)) == \
[(Qubit('10'), S.Half), (Qubit('01'), S.Half)]
assert measure_partial(state, int(0)) == \
[(Qubit('10'), S.Half), (Qubit('01'), S.Half)]
assert measure_partial(state, (0,)) == \
measure_partial(state, (1,))[::-1]
#Test of more complex collapse and probability calculation
state1 = sqrt(2)/sqrt(3)*Qubit('00001') + 1/sqrt(3)*Qubit('11111')
assert measure_partial(state1, (0,)) == \
[(sqrt(2)/sqrt(3)*Qubit('00001') + 1/sqrt(3)*Qubit('11111'), 1)]
assert measure_partial(state1, (1, 2)) == measure_partial(state1, (3, 4))
assert measure_partial(state1, (1, 2, 3)) == \
[(Qubit('00001'), Rational(2, 3)), (Qubit('11111'), Rational(1, 3))]
#test of measuring multiple bits at once
state2 = Qubit('1111') + Qubit('1101') + Qubit('1011') + Qubit('1000')
assert measure_partial(state2, (0, 1, 3)) == \
[(Qubit('1000'), Rational(1, 4)), (Qubit('1101'), Rational(1, 4)),
(Qubit('1011')/sqrt(2) + Qubit('1111')/sqrt(2), S.Half)]
assert measure_partial(state2, (0,)) == \
[(Qubit('1000'), Rational(1, 4)),
(Qubit('1111')/sqrt(3) + Qubit('1101')/sqrt(3) +
Qubit('1011')/sqrt(3), Rational(3, 4))]
def test_measure_all():
assert measure_all(Qubit('11')) == [(Qubit('11'), 1)]
state = Qubit('11') + Qubit('10')
assert measure_all(state) == [(Qubit('10'), S.Half),
(Qubit('11'), S.Half)]
state2 = Qubit('11')/sqrt(5) + 2*Qubit('00')/sqrt(5)
assert measure_all(state2) == \
[(Qubit('00'), Rational(4, 5)), (Qubit('11'), Rational(1, 5))]
# from issue #12585
assert measure_all(qapply(Qubit('0'))) == [(Qubit('0'), 1)]
def test_eval_trace():
q1 = Qubit('10110')
q2 = Qubit('01010')
d = Density([q1, 0.6], [q2, 0.4])
t = Tr(d)
assert t.doit() == 1.0
# extreme bits
t = Tr(d, 0)
assert t.doit() == (0.4*Density([Qubit('0101'), 1]) +
0.6*Density([Qubit('1011'), 1]))
t = Tr(d, 4)
assert t.doit() == (0.4*Density([Qubit('1010'), 1]) +
0.6*Density([Qubit('0110'), 1]))
# index somewhere in between
t = Tr(d, 2)
assert t.doit() == (0.4*Density([Qubit('0110'), 1]) +
0.6*Density([Qubit('1010'), 1]))
#trace all indices
t = Tr(d, [0, 1, 2, 3, 4])
assert t.doit() == 1.0
# trace some indices, initialized in
# non-canonical order
t = Tr(d, [2, 1, 3])
assert t.doit() == (0.4*Density([Qubit('00'), 1]) +
0.6*Density([Qubit('10'), 1]))
# mixed states
q = (1/sqrt(2)) * (Qubit('00') + Qubit('11'))
d = Density( [q, 1.0] )
t = Tr(d, 0)
assert t.doit() == (0.5*Density([Qubit('0'), 1]) +
0.5*Density([Qubit('1'), 1]))
def test_matrix_to_density():
mat = Matrix([[0, 0], [0, 1]])
assert matrix_to_density(mat) == Density([Qubit('1'), 1])
mat = Matrix([[1, 0], [0, 0]])
assert matrix_to_density(mat) == Density([Qubit('0'), 1])
mat = Matrix([[0, 0], [0, 0]])
assert matrix_to_density(mat) == 0
mat = Matrix([[0, 0, 0, 0],
[0, 0, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 0]])
assert matrix_to_density(mat) == Density([Qubit('10'), 1])
mat = Matrix([[1, 0, 0, 0],
[0, 0, 0, 0],
[0, 0, 0, 0],
[0, 0, 0, 0]])
assert matrix_to_density(mat) == Density([Qubit('00'), 1])