Quantum State Preparation#

prepare(qv, target_array, reversed=False, method='auto')[source]#

This method performs quantum state preparation. Given a vector \(b=(b_0,\dotsc,b_{N-1})\), the function acts as

\[\ket{0} \rightarrow \sum_{i=0}^{N-1}b_i\ket{i}\]

Parameters:

qvQuantumVariable: The quantum variable on which to apply state preparation.
target_arraynumpy.ndarray: The vector \(b\).
reversedboolean: If set to True, the endianness is reversed. The default is False.
methodstr, optional: String to specify the compilation method. Available are qiskit, qswitch and auto. qiskit is more gate-efficient but qswitch can also process dynamic arrays. The default is auto.

Examples

We create a QuantumFloat and prepare the state \(\sum_{i=0}^3b_i\ket{i}\) for \(b=(0,1,2,3)\).

b = np.array([0,1,2,3])

qf = QuantumFloat(2)
prepare(qf, b)

res_dict = qf.get_measurement()

for k, v in res_dict.items():
    res_dict[k] = v**0.5

for k, v in res_dict.items():
    res_dict[k] = v/res_dict[1.0]

print(res_dict)
# Yields: {3: 2.9999766670425863, 2: 1.999965000393743, 1: 1.0}