def main():
num_qbits = 5
num_up = 2
dm = DenMat(1 << num_qbits, tuple([2]*num_qbits))
st = SymNupState(num_up, num_qbits)
st_vec = st.get_st_vec()
dm.set_arr_from_st_vec(st_vec)
ecase = PureStEnt(dm, 'eigen')
pf = ecase.get_entang_profile()
# print(',,...', pf)
ecase.print_entang_profiles([pf, pf], dm.row_shape)
def main3():
print('--------------------main3')
num_qbits = 4
num_up = 2
dm = DenMat(1 << num_qbits, tuple([2]*num_qbits))
st = SymNupState(num_up, num_qbits)
st_vec = st.get_st_vec()
dm.set_arr_from_st_vec(st_vec)
# dm.depurify(.1)
exact_evas = np.linalg.eigvalsh(dm.arr)
print('evas_of_dm\n', exact_evas, 'sum=', np.sum(exact_evas))
pert = DenMatPertTheory.new_with_separable_dm0(dm, verbose=True)
num_steps = 80
main_test(dm, exact_evas, pert, num_steps)
def main():
print('4 Bell Basis states**********************')
for bits_are_equal in [True, False]:
for mid_sign in ['+', '-']:
st_vec = OtherStates.get_bell_basis_st_vec(bits_are_equal, mid_sign)
dm = DenMat(4, (2, 2))
dm.set_arr_from_st_vec(st_vec)
ecase = PureStEnt(dm)
pf = ecase.get_entang_profile()
print('----------bits_are_equal=', bits_are_equal,
', mid_sign=', mid_sign)
print("st_vec=\n", st_vec)
ecase.print_entang_profiles([pf], dm.row_shape)
print('bound entang state **********************')
dm_bd = OtherStates.get_den_mat_with_bound_entang(.5)
num_hidden_states = 5
num_ab_steps = 30
ecase = SquashedEnt(dm_bd, num_hidden_states, num_ab_steps,
verbose=True)
pf = ecase.get_entang_profile()
ecase.print_entang_profiles([pf], dm_bd.row_shape)
def main1():
print('4 Bell Basis states**********************')
for key in TwoQubitState.bell_key_set():
st_vec = TwoQubitState.get_bell_basis_st_vec(key)
dm = DenMat(4, (2, 2))
dm.set_arr_from_st_vec(st_vec)
ecase = PureStEnt(dm)
pf = ecase.get_entang_profile()
print('----------key:', key)
print("st_vec=\n", st_vec)
ecase.print_entang_profiles([pf], dm.row_shape)
print("*******************************")
dm1 = TwoQubitState.get_bell_basis_diag_dm(fid=.7)
# print('arr=\n', dm1.arr)
np.random.seed(123)
dm2 = DenMat(4, (2, 2))
dm2.set_arr_to_rand_den_mat(np.array([.1, .2, .3, .4]))
dm3 = DenMat(4, (2, 2))
dm3.set_arr_to_rand_den_mat(np.array([.1, .1, .1, .7]))
for dm in [dm1, dm2, dm3]:
print("----------new dm")
print("formation_entang=",
TwoQubitState.get_known_formation_entang(dm))
def check_max_entang_st(st):
"""
This method checks that the object st of class MaxEntangState does
indeed carry maximal entanglement. The entanglement is calculated 3
different ways (von Neumann entropy of 2 partial traces of density
matrix, and from known value) and the 3 values are checked to agree.
Parameters
----------
st : MaxEntangState
Returns
-------
None
"""
dm = DenMat(st.num_rows, st.row_shape)
st_vec = st.get_st_vec()
dm.set_arr_from_st_vec(st_vec)
ent1 = dm.get_partial_tr(set(st.y_axes)).get_entropy()
ent2 = dm.get_partial_tr(set(st.x_axes)).get_entropy()
ent3 = np.log(st.num_vals_min)
assert abs(ent1 - ent2) < 1e-6 and abs(ent1 - ent3) < 1e-6, \
str(ent1) + ', ' + str(ent2) + ', ' + str(ent3)
