quantum_info Module

The pyqpanda3.quantum_info module provides core quantum information primitives: quantum state representations, quantum channel representations, analysis metrics, and utility classes for matrix operations.

Overview

The module is organized into the following areas:

• Quantum states -- Representations of pure and mixed quantum states via StateVector and DensityMatrix.
• Quantum channels -- Five equivalent representations of completely positive trace-preserving maps: Kraus, Chi, Choi, SuperOp, and PTM.
• Unitary operations -- Extraction of unitary matrices from quantum circuits via Unitary.
• Matrix utilities -- A general-purpose complex Matrix class with algebraic operations.
• Analysis functions -- Statistical distance metrics between probability distributions: Hellinger distance, Hellinger fidelity, and KL divergence.

All classes in this module are exposed under the pyqpanda3.quantum_info namespace.

from pyqpanda3.quantum_info import (
    StateVector, DensityMatrix, Unitary, Matrix,
    Kraus, Chi, Choi, SuperOp, PTM,
    hellinger_distance, hellinger_fidelity, KL_divergence,
)

Sub-topics

Topic	Description
Analysis	Distance metrics: hellinger_distance, hellinger_fidelity, KL_divergence
Matrix	General-purpose complex Matrix class
StateVector	Pure quantum state representation
DensityMatrix	Mixed quantum state representation
Unitary	Unitary operator extracted from a quantum circuit
QuantumChannel	Chi, Choi, SuperOp, PTM, Kraus channel representations