def center(L, config):
len_cent = int(config[0])
len_back = L - len_cent
len_L = int(len_back / 2)
len_R = len_back - len_L
cent_IC = [(config[1:], 1.0)]
left = fock(len_L, 0)
cent = make_state(len_cent, cent_IC)
right = fock(len_R, 0)
if len_back == 0:
return cent
elif len_back == 1:
return mx.listkron([cent, right])
else:
return mx.listkron([left, cent, right])
def fock(L, config, zero='0', one='1'):
dec = int(config)
state = [
el.replace('0', zero).replace('1', one)
for el in list('{0:0b}'.format(dec).rjust(L, '0'))
]
return mx.listkron([bvecs[key] for key in state])
def qubits(L, config):
Tt, Pp = config.split('_')
ang_dict = {
'T': np.linspace(0.0, pi * float(Tt[1:]), L),
't': [float(Tt[1:]) * pi / 180.0] * L,
'P': np.linspace(0.0, 2 * pi * float(Pp[1:]), L),
'p': [float(Pp[1:]) * pi / 180.0] * L,
}
th_list = ang_dict[Tt[0]]
ph_list = ang_dict[Pp[0]]
qubit_list = [0.0] * L
for j, (th, ph) in enumerate(zip(th_list, ph_list)):
qubit_list[j] = qubit(th, ph)
return mx.listkron(qubit_list)
def rand_state(L, config):
# default background state (DOWN state)
bg = np.array([0, 1], dtype=complex)
# default state to be distribute among the background
state = np.array([1, 0], dtype=complex)
# get the probability specified in config
state_prob = eval('.' + config)
# array to hold the probabilities of state and bg
prob = [state_prob, 1 - state_prob]
# get random distribution of states based on prob
states = [state, bg]
distrib = np.random.choice([0, 1], size=L, p=prob)
# kronecker the states in the distribution and return
return mx.listkron([states[i] for i in distrib])
def ghz(L, congif):
s1 = ['1'] * (L)
s2 = ['0'] * (L)
return (1.0/sqrt(2.0)) \
* ((mx.listkron([bvecs[key] for key in s1]) \
+ mx.listkron([bvecs[key] for key in s2])))
