Pure Fock simulation with Tensorflow#

[2]:

import numpy as np
import piquasso as pq
import tensorflow as tf


theta_1 = tf.Variable(np.pi / 3)
theta_2 = tf.Variable(np.pi / 5)

simulator = pq.TensorflowPureFockSimulator(d=3, config=pq.Config(cutoff=3))

with pq.Program() as program:
    pq.Q(all) | pq.StateVector((1, 1, 0))

    pq.Q(0, 1) | pq.Beamsplitter(theta=theta_1)
    pq.Q(1, 2) | pq.Beamsplitter(theta=theta_2)

with tf.GradientTape() as tape:
    state = simulator.execute(program).state

    fock_probabilities = state.fock_probabilities

tape.jacobian(fock_probabilities, [theta_1, theta_2])

[2]:

[<tf.Tensor: shape=(10,), dtype=float32, numpy=
 array([ 0.        ,  0.        ,  0.        ,  0.        , -0.8660257 ,
         1.1336422 ,  0.59840894, -0.37098926, -0.39166376, -0.1033726 ],
       dtype=float32)>,
 <tf.Tensor: shape=(10,), dtype=float32, numpy=
 array([ 0.        ,  0.        ,  0.        ,  0.        ,  0.        ,
        -0.23776424,  0.23776422, -0.46685594,  0.22041947,  0.24643645],
       dtype=float32)>]