def run_and_create(n):
inputfile = open('./Task2Code/input_for_exercise3.txt', "r")
N = int(inputfile.readline()) #Number of Atoms
nmodes = 3 * N - 6 #Number of Modes
w = np.zeros(nmodes, float) #vib. frequencies of ground electronic state
wp = np.zeros(nmodes, float) #vib. frequencies of excited electronic state
Ud = np.zeros((nmodes, nmodes), float) #Duschinsky Matrix
delta = np.zeros(nmodes, float) #Displacement Vector
###############################
##### READ IN PARAMETERS ######
###############################
for i in range(nmodes):
w[i] = float(inputfile.readline())
for i in range(nmodes):
wp[i] = float(inputfile.readline())
for i in range(nmodes):
for j in range(nmodes):
Ud[i, j] = float(inputfile.readline())
for i in range(nmodes):
delta[i] = float(inputfile.readline())
T = 500 # temperature
#####################################
##### CALCULATE GBS PARAMETERS ######
#####################################
t, U1, r, U2, alpha = vibronic.gbs_params(w, wp, Ud, delta, T)
###############################
###### GENERATE SAMPLES #######
###############################
nr_samples = n
s = sample.vibronic(t, U1, r, U2, alpha, nr_samples)
e = vibronic.energies(s, w, wp)
###############################
######## PLOT SPECTRUM ########
###############################
spectrum = plot.spectrum(e, xmin=-300, xmax=2000)
offline.plot(spectrum, filename="spectrum_{}_samples.html".format(n))
from :cite:`huh2015boson`, can be found in the :mod:`~.apps.data` module: """ from strawberryfields.apps import vibronic, data import numpy as np formic = data.Formic() w = formic.w # ground state frequencies wp = formic.wp # excited state frequencies Ud = formic.Ud # Duschinsky matrix delta = formic.delta # displacement vector T = 0 # temperature ############################################################################## # We can now map this chemical information to GBS parameters using the function # :func:`~.gbs_params`: t, U1, r, U2, alpha = vibronic.gbs_params(w, wp, Ud, delta, T) ############################################################################## # Note that since two-mode squeezing operators are involved, if we have :math:`N` vibrational # modes, the Gaussian state prepared is a :math:`2N`-mode Gaussian state and the samples # are vectors of length :math:`2N`. The first :math:`N` modes are those of the final electronic # state; the remaining :math:`N` modes are those of the ground state. From above, :math:`t` is a # vector of two-mode squeezing parameters, :math:`U_1` and :math:`U_2` are the interferometer # unitaries (we need two interferometers), :math:`r` is a vector of single-mode squeezing # parameters, and `alpha` is a vector of displacements. # # Photons detected at the output of the GBS device correspond to a specific transition energy. # The GBS algorithm for vibronic spectra works because the programmed device provides samples # in such a way that the energies that are sampled with high probability are the peaks of the # vibronic spectrum. The function :func:`~.energies` can be used to compute the energies for # a set of samples. In this case we show the energy of the first five samples:
def test_invalid_temperature(self):
"""Test if function raises a ``ValueError`` when a negative temperature is given."""
with pytest.raises(ValueError,
match="Temperature must be zero or positive"):
vibronic.gbs_params(self.w, self.wp, self.Ud, self.d, -1)
def test_zero_temperature(self):
"""Test if function returns zero two-mode squeezing parameters when temperature is zero."""
t, _, _, _, _ = vibronic.gbs_params(self.w, self.wp, self.Ud, self.d,
0.0)
assert np.all(t == 0)
class TestGBSParams:
"""Tests for the function ``strawberryfields.apps.vibronic.gbs_params``"""
dim = 7
w = np.array([
3765.2386, 3088.1826, 1825.1799, 1416.9512, 1326.4684, 1137.0490,
629.7144
])
wp = np.array([
3629.9472, 3064.9143, 1566.4602, 1399.6554, 1215.3421, 1190.9077,
496.2845
])
Ud = np.array([
[0.9934, 0.0144, 0.0153, 0.0268, 0.0638, 0.0751, -0.0428],
[-0.0149, 0.9931, 0.0742, 0.0769, -0.0361, -0.0025, 0.0173],
[-0.0119, -0.0916, 0.8423, 0.1799, -0.3857, 0.3074, 0.0801],
[0.0381, 0.0409, -0.3403, -0.5231, -0.6679, 0.3848, 0.1142],
[-0.0413, -0.0342, -0.4004, 0.7636, -0.1036, 0.4838, 0.0941],
[0.0908, -0.0418, -0.0907, 0.3151, -0.5900, -0.7193, 0.1304],
[-0.0325, 0.0050, -0.0206, 0.0694, -0.2018, 0.0173, -0.9759],
])
d = np.array([0.2254, 0.1469, 1.5599, -0.3784, 0.4553, -0.3439, 0.0618])
T = 300.0
t, U1, S, U2, alpha = vibronic.gbs_params(w, wp, Ud, d, T)
@pytest.mark.parametrize("unitary", [U1, U2])
def test_unitary(self, unitary):
"""Test if function outputs the interferometer unitaries that are valid unitaries,
i.e., satisfying U U^dag = I"""
assert unitary.shape == (self.dim, self.dim)
assert np.allclose(unitary @ unitary.T.conj(), np.identity(self.dim))
def test_displacement(self):
"""Test if function returns correct displacement parameters"""
assert np.allclose(self.alpha * np.sqrt(2), self.d)
def test_squeezing(self):
"""Test if function returns squeezing parameters as a vector rather than a diagonal
matrix"""
assert self.S.shape == (self.dim, )
def test_duschinsky(self):
"""Test if function returns interferometer unitary and squeezing parameters that
correctly reconstruct the input Duschinsky matrix"""
sigma = np.diag(np.exp(self.S))
J = self.U2 @ sigma @ self.U1
Ud = np.diag(self.wp**-0.5) @ J @ np.diag(self.w**0.5)
assert np.allclose(Ud, self.Ud)
def test_invalid_temperature(self):
"""Test if function raises a ``ValueError`` when a negative temperature is given."""
with pytest.raises(ValueError,
match="Temperature must be zero or positive"):
vibronic.gbs_params(self.w, self.wp, self.Ud, self.d, -1)
def test_twomode(self):
"""Test if function returns two-mode squeezing parameters that correctly reconstruct the
input normal mode frequencies."""
w = -k * self.T / (0.5 * h * c * 100) * np.log(np.tanh(self.t))
assert np.allclose(w, self.w)
def test_zero_temperature(self):
"""Test if function returns zero two-mode squeezing parameters when temperature is zero."""
t, _, _, _, _ = vibronic.gbs_params(self.w, self.wp, self.Ud, self.d,
0.0)
assert np.all(t == 0)