Variational Data Encoding
Encoding classical data on quantum states is an important subroutine in variational quantum circuits, such as Quantum Singular Vector Machine (QSVM) and Quantum Neural Networks (QNN).
Encode in angle
This function encodes \(n\) data points on \(n\) qubits, mapping the data point \(x_i\) to a RY rotation on the \(i\)-th qubit with a \(\pi x_i\) angle.
Function: encode_in_angle
Arguments:
-
data:CArray[Creal] -
qba:Output[QArray[QBit]]
The qba quantum argument is the quantum state on which we encode the classical array data.
Example
from classiq import *
@qfunc
def main(data: CArray[CReal, 4], x: Output[QArray[QBit]]):
encode_in_angle(data, x)
qmod = create_model(main)
from classiq import synthesize, write_qmod
write_qmod(qmod, "encode_in_angle")
qprog = synthesize(qmod)
Encode on Bloch
This function encodes \(n\) data points on \(\lceil n/2 \rceil\), mapping pairs of data points \((x_{2i}, x_{2i+1})\) to the bloch sphere via RX rotation with an angle \(\pi x_{2i}\) followed by a RZ rotation with an angle \(\pi x_{2i+1}\). If the number of data points is odd then a single RX rotation is applied to the last qubit, with an angle of \(2\pi x_n\).
Function: encode_on_bloch
Arguments:
-
data:CArray[Creal] -
qba:Output[QArray[QBit]]
The qba quantum argument is the quantum state on which we encode the classical array data.
Example
from classiq import *
@qfunc
def main(data: CArray[CReal, 7], x: Output[QArray[QBit]]):
encode_on_bloch(data, x)
qmod = create_model(main)
from classiq import synthesize, write_qmod
write_qmod(qmod, "encode_on_bloch")
qprog = synthesize(qmod)
