quairkit.ansatz.encoding¶
The source file of encoding layers for classical data, including - Basic encoding - Amplitude encoding - Angle encoding - IQP encoding
- class quairkit.ansatz.encoding.BasisEncoding(data, qubits_idx)¶
Basis encoding for classical data.
Encodes an integer into a computational basis state:
\[U_{\text{basic}}|0\rangle^{\otimes n} = |x\rangle\]where \(x\) is the integer to be encoded.
- class quairkit.ansatz.encoding.AmplitudeEncoding(vector, qubits_idx)¶
Amplitude encoding for classical data.
Encodes a vector into quantum state amplitudes:
\[U_{\text{amp}}|0\rangle^{\otimes n} = \sum_{i=0}^{d-1} x_i |i\rangle\]where \(\mathbf{x}\) is the normalized input vector.
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class quairkit.ansatz.encoding.AngleEncoding(angles, qubits_idx, rotation=
'RY')¶ Angle encoding for classical data.
Encodes classical data into rotation angles:
\[|x\rangle = U_{\text{angle}} |0\rangle^{\otimes n} = \bigotimes_{i=1}^{n} R_{\alpha}(\theta_i)|0\rangle^{\otimes n}\]where \(\alpha \in \{X, Y, Z\}\) and \(\theta_i\) are input angles.
- class quairkit.ansatz.encoding.IQPEncoding(features, set_entanglement, qubits_idx, depth)¶
Instantaneous Quantum Polynomial (IQP) encoding.
Implements the encoding:
\[U_{\text{IQP}} = \left( \prod_{(i,j)\in S} R_{z_i z_j}(x_ix_j) \bigotimes_{k=1}^{n} R_z(x_k) H^{\otimes n}\right)^r\]where \(x\) is the integer to be encoded, \(S\) is the set containing all pairs of qubits to be entangled using \(R_{zz}\) gates, and \(r\) is the depth of the circuit.